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Urea
Identifiers
CAS number 57-13-6 Yes check.svgY
PubChem 1176
ChemSpider 1143
RTECS number YR6250000
SMILES
Properties
Molecular formula CH4N2O
Molar mass 60.06 g mol−1
Appearance White solid
Density 1.32 g/cm3
Melting point
132.7–135 °C
Solubility in water 108 g/100 ml (20 °C)
167 g/100 ml (40 °C)
251 g/100 ml (60 °C)
400 g/100 ml (80 °C)
733 g/100 ml (100 °C)
Basicity (pKb) pKBH+ = 0.18[1]
Structure
Dipole moment 4.56 D
Hazards
MSDS JT Baker
EU Index Not listed
Flash point Non-flammable
Related compounds
Related ureas Thiourea
Hydroxycarbamide
Related compounds Carbamide peroxide
Urea phosphate
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references
.Urea or carbamide is an organic compound with the chemical formula (NH2)2CO.^ Urea has the ability to form 'loose compounds' with many organic compounds.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ Urea is considered an organic compound because it contains carbon.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Example of ureas are the compounds carbamide peroxide , allantoin and Hydantoin .
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

.The molecule has two amine (-NH2) residues joined by a carbonyl (-CO-) functional group.^ It is two urea molecules joined together accompanied by the removal of an ammonia molecule.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The disassociation of ammonium carbonate into two (2) molecules of NH 3 plus one (1) molecule each of H 2 O and CO 2 is well known.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ The disassociation of ammonium carbamate into two (2) molecules of NH 3 plus one (1) molecule of CO 2 is also well known, and is nearly irreversible at reaction temperatures in excess of 250 F., as in the present invention.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

.Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals.^ Urea, a white crystalline solid containing 46% nitrogen, is widely used in the agricultural industry as an animal feed additive and fertilizer Here we discuss it only as a nitrogen fertilizer.

^ If properly applied, urea and fertilizers containing urea are excellent sources of nitrogen for crop production.

^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.Being solid, colourless, odorless, neither acidic nor alkaline, highly soluble in water, and relatively non-toxic, urea is widely used in fertilizers as a convenient source of nitrogen.^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ However, urea is the most widely used.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Urea is the fastest growing dry nitrogen fertilizer used by farmers.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.Urea is also an important raw material for the chemical industry.^ Urea is a well-known fertilizer and industrial chemical which is useful for many purposes, including urea-formaldehyde resins and glues.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ Urea is produced commercially from two raw materials, ammonia and carbon dioxide .
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ The raw material for urea and others nitrogenous fertilizers is natural gas.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.The synthesis of this organic compound by Friedrich Wöhler in 1828 from an inorganic precursor was an important milestone in the development of chemistry.^ Wöhler's synthesis marks the beginning of the modern era in organic chemistry.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

.The terms urea and carbamide are also used for a class of chemical compounds sharing the same functional group RR'N-CO-NRR', namely a carbonyl group attached to two organic amine residues.^ Amine-function compounds .
  • Urea - World Market Outlook And Forecast :: 10 January 2010 10 January 2010 9:24 UTC mcgroup.co.uk [Source type: Academic]

^ Ureas or carbamides are a class of chemical compounds sharing the same functional group RR'N-CO-NRR' based on a carbonyl group flanked by two organic amine residues.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ Urea is a well-known fertilizer and industrial chemical which is useful for many purposes, including urea-formaldehyde resins and glues.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

Example include carbamide peroxide, allantoin, and hydantoin. .Ureas are closely related to biurets and related in structure to amides, carbamates, diimides, carbodiimides, and thiocarbamides.^ Ureas are closely related to biurets and structurally related to amides , carbamates , diimides , carbodiimides and thiocarbamides .
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ Abiotic hydrolysis of       urea occurs very slowly in relation to biotic hydrolysis(6); abiotic       hydrolysis yields ammonium carbamate which decomposes to form CO2 and       ammonia(6); the enzyme urease catalyzes urea hydrolysis(6).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Contents

History

.Urea was first discovered in urine in 1773 by the French chemist Hilaire Rouelle.^ Hilaire Marin Rouelle (1718 – 1779) was a French chemist.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ In 1773, he discovered urea.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ Urea was discovered by Hilaire Rouelle in 1773 .
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

In 1828, the German chemist Friedrich Wöhler obtained urea by treating silver isocyanate with ammonium chloride in a failed attempt to prepare ammonium cyanate:[2]
AgNCO + NH4Cl → (NH2)2CO + AgCl
.This was the first time an organic compound was artificially synthesized from inorganic starting materials, without the involvement of living organisms.^ It was the first organic compound ever synthesized by chemists; this was accomplished in the early 1800s.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ This achievement definitively overthrew the vitalist theory that organic (vital) and inorganic (nonvital) chemicals were fundamentally different, so that organic chemicals could not ( ex hypothesi ) be synthesized completely from inorganic chemicals.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

.The results of this experiment implicitly discredited vitalism: the theory that the chemicals of living organisms are fundamentally different from inanimate matter.^ This achievement definitively overthrew the vitalist theory that organic (vital) and inorganic (nonvital) chemicals were fundamentally different, so that organic chemicals could not ( ex hypothesi ) be synthesized completely from inorganic chemicals.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

This insight was important for the development of organic chemistry. .His discovery prompted Wöhler to write triumphantly to Berzelius: "I must tell you that I can make urea without the use of kidneys, either man or dog.^ Do not use any other skin products on the affected area without telling your doctor or health care professional.

^ Marked brain damage is seen in cases of failure to make urea via the urea cycle or to eliminate urea through the kidneys.

^ You can really tell what difference it makes when mixing the dies Was this review helpful to you?

.Ammonium cyanate is urea."^ In 1828, Friedrich Wöhler (1800-1882) synthesized urea from ammonium cyanate.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

For this discovery, Wöhler is considered by many the father of organic chemistry.

Physiology

.Urea is synthesized in the body of many organisms as part of the urea cycle, either from the oxidation of amino acids or from ammonia.^ The urea cycle is a process in which waste (ammonia) is removed from the body.
  • Hereditary Urea Cycle Abnormality | LIVESTRONG.COM 10 January 2010 9:24 UTC www.livestrong.com [Source type: FILTERED WITH BAYES]

^ The exact means       by which ammonia blocks the citric acid cycle is not known.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Abnormal amino acids in blood and urine Abnormal level of orotic acid in blood or urine High blood ammonia level Normal level of acid in blood Tests may include: .
  • Hereditary Urea Cycle Abnormality | LIVESTRONG.COM 10 January 2010 9:24 UTC www.livestrong.com [Source type: FILTERED WITH BAYES]

.In this cycle, amino groups donated by ammonia and L-aspartate are converted to urea, while L-ornithine, citrulline, L-argininosuccinate, and L-arginine act as intermediates.^ The reaction involves the addition of AMP (from ATP) to the amido carbonyl of citrulline, forming an activated intermediate on the enzyme surface (AMP-citrulline), and the subsequent addition of aspartate to form argininosuccinate.

^ Carbamyl phosphate reacts with ornithine to form citrulline which combines with aspartate to form argininosuccinate.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ The urea cycle is a process in which waste (ammonia) is removed from the body.
  • Hereditary Urea Cycle Abnormality | LIVESTRONG.COM 10 January 2010 9:24 UTC www.livestrong.com [Source type: FILTERED WITH BAYES]

.Urea production occurs in the liver and is regulated by N-acetylglutamate.^ Short-term regulation of the cycle occurs principally at CPS-I, which is relatively inactive in the absence of its allosteric activator N -acetylglutamate.

^ Urea occurs naturally in mammals and is an excretory end-product of amino acid metabolism.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

.Urea is found dissolved in blood (in the reference range of 2.5 to 7.5 mmol/liter) and is excreted by the kidney as a component of urine.^ No toxic effects were found in humans if the blood urea-nitrogen was below 45 mg/100 ml (approx.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ If your kidneys are not able to remove urea from the blood normally, your BUN level rises.
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

^ Fifty-two per cent of the administered 15 N-labelled urea was excreted in the urine after 48 hours and 1.9% during the subsequent 48 hours.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

.In addition, a small amount of urea is excreted (along with sodium chloride and water) in sweat.^ In addition, urea is less acid forming, is more water soluble and less corrosive.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The postdialysis BUN sample was drawn following a very efficient hemodialysis in a patient with a small V (high K/V), resulting in urea disequilibrium in the body water compartment.
  • NKF KDOQI Guidelines 10 January 2010 9:24 UTC www.kidney.org [Source type: Academic]

^ Children have a smaller body and relatively higher total body water and are therefore at increased risk for significant amounts of urea rebound.
  • NKF KDOQI Guidelines 10 January 2010 9:24 UTC www.kidney.org [Source type: Academic]

Reference ranges for blood tests, comparing blood content of urea (shown in yellow) with other constituents.
The same information, shown in molarity rather than mass.
.Amino acids from ingested food which are not used for the synthesis of proteins and other biological substances are oxidized by the body, yielding urea and carbon dioxide, as an alternative source of energy.^ Large boluses of protein or amino acid .
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ On high-protein diets the carbon skeletons of the amino acids are oxidized for energy or stored as fat and glycogen, but the amino nitrogen must be excreted.

^ The amino acids arginine, methionine and phenylalanine are considered essential for reasons not directly related to lack of synthesis.

[3] .The oxidation pathway starts with the removal of the amino group by a transaminase, the amino group is then fed into the urea cycle.^ This is because the convective transfer of urea that occurs by ultrafiltration does not result in a decrease in the BUN concentration, although urea removal into the dialysate has occurred.
  • NKF KDOQI Guidelines 10 January 2010 9:24 UTC www.kidney.org [Source type: Academic]

^ Affected individuals are able to incorporate some waste nitrogen into urea cycle intermediates, which makes treatment slightly easier.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ This enzyme defect is past the point in the metabolic pathway at which all the waste nitrogen has been incorporated into the cycle.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.Ammonia (NH3) is another common byproduct of the metabolism of nitrogenous compounds.^ When glutamine enters the kidney, glutaminase releases one mole of ammonia generating glutamate and then glutamate dehydrogenase releases another mole of ammonia generating α-KG. The ammonia will ionizes to ammonium ion (NH 4 + ) which is excreted.

^ Bacteria metabolize levulose to acidic byproducts which then promotes excretion of ammonia in the feces as ammonium ions, NH 4 + .

^ These latter compounds, which contain the ammonia nitrogen, are excreted in the feces.

.Ammonia molecules are smaller, more volatile and more mobile than urea's.^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea supplies more nitrogen per ton of product than any other dry fertilizer.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ It is two urea molecules joined together accompanied by the removal of an ammonia molecule.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

If allowed to accumulate, ammonia would raise the pH in cells to toxic levels. .Therefore many organisms convert ammonia to urea, even though this synthesis has a net energy cost.^ In the forward reaction as shown above glutamate dehydrogenase is important in converting free ammonia and α-KG to glutamate, forming one of the 20 amino acids required for protein synthesis.

^ The energy consumed in the production of urea is more than recovered by the release of energy formed during the synthesis of the urea cycle intermediates.

^ Thus, in the present study energy from molasses and N from urea and soybean of the supplements may be available for microbial protein synthesis.
  • Effect of urea 10 January 2010 9:24 UTC www.mekarn.org [Source type: Academic]

.Being practically neutral and highly soluble in water, urea is a safe vehicle for the body to transport and excrete excess nitrogen.^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Since urea transport can be assumed as flow limited, any increase in muscle blood flow will increase total body clearance and dialysis efficiency.
  • Low-potassium and glucose-free dialysis maintains urea but enhances potassium removal -- Zehnder et al. 16 (1): 78 -- Nephrology Dialysis Transplantation 10 January 2010 9:24 UTC ndt.oxfordjournals.org [Source type: Academic]

^ Urea is a white crystalline substance with the chemical formula CO(NH2)2; it is highly water soluble and contains 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

In humans

The handling of urea by the kidneys is a vital part of human metabolism. .Besides its role as carrier of waste nitrogen, urea also plays a role in the countercurrent exchange system of the nephrons, that allows for reabsorption of water and critical ions from the excreted urine.^ Affected individuals are able to incorporate some waste nitrogen into urea cycle intermediates, which makes treatment slightly easier.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Urea is a white crystalline substance with the chemical formula CO(NH2)2; it is highly water soluble and contains 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ PEER REVIEWED** ENVIRONMENTAL FATE & EXPOSURE: ENVIRONMENTAL FATE/EXPOSURE SUMMARY:       Urea occurs naturally in urine and animal waste and can be formed       naturally in the environment through protein metabolism.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Urea is reabsorbed in the inner medullary collecting ducts of the nephrons,[4] thus raising the osmolarity in the medullary interstitium surrounding the thin ascending limb of the loop of Henle, which in turn causes water to be reabsorbed. .By action of the urea transporter 2, some of this reabsorbed urea will eventually flow back into the thin ascending limb of the tubule, through the collecting ducts, and into the excreted urine.^ Affected individuals are able to incorporate some waste nitrogen into urea cycle intermediates, which makes treatment slightly easier.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Urea present in the blood of ruminants appears to be actively transported across the rumen wall into the lumen and used as a nitrogen source (Schmidt-Nielsen, 1958).
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ Fifty-two per cent of the administered 15 N-labelled urea was excreted in the urine after 48 hours and 1.9% during the subsequent 48 hours.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

.This mechanism, which is controlled by the antidiuretic hormone, allows the body to create hyperosmotic urine, that has a higher concentration of dissolved substances than the blood plasma.^ Less than 1% of the 15 N was found in the liver, muscle and blood cells, study concluded that this indicates incorporation of 15 N in body proteins.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ A plasma ammonia concentration of 150 mmol/L or higher, associated with a normal anion gap and a normal serum glucose concentration, is a strong indication of a UCD [ Summar & Tuchman 2001 ].
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Potassium-free dialysate removed 85% more potassium than 2K and 46% more than 1K. Interestingly, potassium removal could not be predicted by modelling plasma potassium concentrations.
  • Low-potassium and glucose-free dialysis maintains urea but enhances potassium removal -- Zehnder et al. 16 (1): 78 -- Nephrology Dialysis Transplantation 10 January 2010 9:24 UTC ndt.oxfordjournals.org [Source type: Academic]

.This mechanism is important to prevent the loss of water, to maintain blood pressure, and to maintain a suitable concentration of sodium ions in the blood plasma.^ Initial blood urea concentration, total body water and urea mass of the patients were not different during the study HDs as well (Table 1 ).
  • Low-potassium and glucose-free dialysis maintains urea but enhances potassium removal -- Zehnder et al. 16 (1): 78 -- Nephrology Dialysis Transplantation 10 January 2010 9:24 UTC ndt.oxfordjournals.org [Source type: Academic]

In other species

.In aquatic organisms the most common form of nitrogen waste is ammonia, while land-dwelling organisms convert the toxic ammonia to either urea or uric acid.^ PEER REVIEWED** ENVIRONMENTAL FATE & EXPOSURE: ENVIRONMENTAL FATE/EXPOSURE SUMMARY:       Urea occurs naturally in urine and animal waste and can be formed       naturally in the environment through protein metabolism.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ No toxic effects were found in humans if the blood urea-nitrogen was below 45 mg/100 ml (approx.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ Affected individuals are able to incorporate some waste nitrogen into urea cycle intermediates, which makes treatment slightly easier.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

Urea is found in the urine of mammals and amphibians, as well as some fish. .Birds and saurian reptiles have a different form of nitrogen metabolism, that requires less water and leads to nitrogen being excreted in the form of uric acid.^ In addition, all the nitrogen is in the ammonic form and, until nitrification occurs, it is less subject to leaching or de-nitrification than the nitrate portion of the ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ In addition, urea is less acid forming, is more water soluble and less corrosive.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.It is noteworthy that tadpoles excrete ammonia but shift to urea production during metamorphosis.^ Ultimate urea       degradation produces ammonia and CO2 as volatile products(5).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Despite the generalization above, the urea pathway has been documented not only in mammals and amphibians but in many other organisms as well, including birds, invertebrates, insects, plants, yeast, fungi, and even microorganisms.^ It only makes sense if you have well established connections and other business interests in the country with the possibility of counter-trade.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Fertilizer, solid, 42%; fertilizer solutions, 31%;       exports, 13%; urea-formaldehyde resins and adhesives, 5%; other, including       animal feeds and melamine, 9%.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

[citation needed]

Uses

Agriculture

.More than 90% of world production of urea is destined for use as a nitrogen-release fertilizer.^ Urea supplies more nitrogen per ton of product than any other dry fertilizer.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Do not use it more often than directed.

^ Urea is the fastest growing dry nitrogen fertilizer used by farmers.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use (46.7%).^ Urea is 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is the fastest growing dry nitrogen fertilizer used by farmers.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Is the nitrogen in urea different from nitrogen in "organic fertilizers" in terms of plant nutrition?
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.Therefore, it has the lowest transportation costs per unit of nitrogen nutrient.^ Because urea has the highest analysis (46% nitrogen), it has the lowest application cost per pound of nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The higher nitrogen content means lower transportation and application costs per pound of nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The high analysis means a reduced transportation and application cost per pound of nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.In the soil, it hydrolyses to ammonia and carbon dioxide.^ PEER REVIEWED** METHODS OF MANUFACTURING:       DEHYDRATION OF AMMONIUM CARBONATE WHICH IS SYNTHESIZED FROM AMMONIA AND       CARBON DIOXIDE. [SRI]**PEER REVIEWED**       ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

The ammonia is oxidized by bacteria in the soil to nitrate which can be absorbed by the plants. .Urea is also used in many multi-component solid fertilizer formulations.^ Of utmost concern to many producers in Arkansas and the rest of the U.S. is the dramatic rise in nitrogen fertilizer prices, particularly urea.
  • Nitrogen fertilizer situation and outlook 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

^ Urea is safer to ship and handle, it is less corrosive to equipment, it has a higher analysis than any other dry nitrogen fertilizer and it can be used on virtually all crops.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is the fastest growing dry nitrogen fertilizer used by farmers.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.Urea is highly soluble in water and is, therefore, also very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g., in 'foliar feed' fertilizers.^ Ammonium Nitrate, UAN Solution, NPK, etc.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ From urea and ammonium nitrate the factory produces UAN Solution; .
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.For fertilizer use, granules are preferred over prills because of their narrower particle size distribution which is an advantage for mechanical application.^ Is it related to how the spreader machines/ applicators use bigger granulation, and hand/manually spread use prill /smaller granulation?
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

The most common impurity of synthetic urea is biuret, which impairs plant growth.
.Urea is usually spread at rates of between 40 and 300 kg/ha but rates vary.^ Increasing growth rates of cattle in the wet season using supplements of molasses/urea combined with various protein sources.
  • Effect of urea 10 January 2010 9:24 UTC www.mekarn.org [Source type: Academic]

^ Product Rating: Reviewed: Sat May 2 08:42:40 2009 Urea had a few foreign pieces in there, but not as much as if I were to get it from the lawn and garden store.

^ PEER REVIEWED**       TOXIC DOSE IN CATTLE GIVEN UREA FOR FIRST TIME IS VARIOUSLY CONSIDERED TO       BE 0.45 G/KG ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Smaller applications incur lower losses due to leaching. .During summer, urea is often spread just before, or during rain to minimize losses from volatilization (process wherein nitrogen is lost to the atmosphere as ammonia gas).^ Urea is a 'moisture drawing' agent which keeps the fabric damper longer during the curing or fixing process, thereby making for deeper, brighter colors.

^ The factory using natural gas, steam and electricity to produce ammonia and from that urea and ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ This extra nitrogen is converted into ammonia (NH4) and transported to the liver where it is processed.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.Urea is not compatible with other fertilizers.^ Fertilizer, solid, 42%; fertilizer solutions, 31%;       exports, 13%; urea-formaldehyde resins and adhesives, 5%; other, including       animal feeds and melamine, 9%.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Because of the high nitrogen concentration in urea, it is very important to achieve an even spread.^ Six healthy human subjects were maintained at serum urea-nitrogen concentrations at 60 to 120 mg/100 ml (approx.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ Urea itself is very mobile because it is a neutral molecule, it has no charge and is not attracted to soil particles.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ In the very near future urea is expected to account for more than 50% of the nitrogen fertilizer in world trade.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

The application equipment must be correctly calibrated and properly used. Drilling must not occur on contact with or close to seed, due to the risk of germination damage. .Urea dissolves in water for application as a spray or through irrigation systems.^ Urea can be stored and distributed through conventional systems.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Particulate-phase urea and aerosols released       to air during spray applications of urea fertilizers will be removed from       air physically by dry and wet deposition(SRC).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Just use warm Urea water (1 TBS per Cup) to paste up your dye to get it more thoroughly dissolved.

In grain and cotton crops, urea is often applied at the time of the last cultivation before planting. .In high rainfall areas and on sandy soils (where nitrogen can be lost through leaching) and where good in-season rainfall is expected, urea can be side- or top-dressed during the growing season.^ Once in the soil, however, it is rapidly converted into ammonic nitrogen, which is attracted to the soil particles, thus preventing leaching loss.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ In the very near future urea is expected to account for more than 50% of the nitrogen fertilizer in world trade.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ However, much of the urea exchanged ions will migrate downward       /SRP: as well as lateral/ through the soil.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Top-dressing is also popular on pasture and forage crops. In cultivating sugarcane, urea is side-dressed after planting, and applied to each ratoon crop.
.In irrigated crops, urea can be applied dry to the soil, or dissolved and applied through the irrigation water.^ Biuret is of little concern for soil-applied nitrogen fertilizers, but it can be toxic when nitrogen fertilizers containing biuret are foliar-applied to sensitive crops such as citrus or pineapple.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ However, much of the urea exchanged ions will migrate downward       /SRP: as well as lateral/ through the soil.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Urea will dissolve in its own weight in water, but it becomes increasingly difficult to dissolve as the concentration increases.^ The relationship between plasma urea concentration and low birth weight in infants of non-toxaemic mothers was investigated.
  • 798. Urea (WHO Food Additives Series 32) 10 January 2010 9:24 UTC www.inchem.org [Source type: Academic]

^ Urea poisoning in sheep is associated with an       elevated blood ammonia concentration, increased erythrocyte counts and       packed cell volume values, and decreased leucocyte counts ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ The short term feeding of protein concentrates before       giving urea supplements can increase sheep's tolerance to urea ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Dissolving urea in water is endothermic, causing the temperature of the solution to fall when urea dissolves.^ It dissolved easily and didn't cause any discoloration to the water.

^ Just use warm Urea water (1 TBS per Cup) to paste up your dye to get it more thoroughly dissolved.

^ CARDIOVASCULAR    0.2.5.1 ACUTE EXPOSURE      o   WITH THERAPEUTIC USE       1.  Therapeutic administration of intravenous solutions           may cause a fall in blood pressure.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.As a practical guide, when preparing urea solutions for fertigation (injection into irrigation lines), dissolve no more than 30 kg urea per 100 L water.^ Made the dye dissolve more easily into water.

^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.In foliar sprays, urea concentrations of 0.5% – 2.0% are often used in horticultural crops.^ Urea is safer to ship and handle, it is less corrosive to equipment, it has a higher analysis than any other dry nitrogen fertilizer and it can be used on virtually all crops.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

Low-biuret grades of urea are often indicated.
.Urea absorbs moisture from the atmosphere and therefore is typically stored either in closed/sealed bags on pallets, or, if stored in bulk, under cover with a tarpaulin.^ Urea can be practically dust-free and, under most conditions, it does not absorb moisture and cake up.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.As with most solid fertilizers, storage in a cool, dry, well-ventilated area is recommended.^ Our recommendation is to try and delay the fertilizer and flood until the soil dries out.
  • Agrotain: boosting urea efficiency 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

Chemical industry

Urea is a raw material for the manufacture of many important chemical compounds, such as

Automobile systems

.Urea is used in SNCR and SCR reactions to reduce the NOx pollutants in exhaust gases from combustion, for example, from power plants and diesel engines.^ In the western U.S., for example, urea use has increased from 28,000 tons in 1955 to 390,000 in 1989, a 15-fold increase.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.The BlueTec system, for example, injects water-based urea solution into the exhaust system.^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.The ammonia produced by decomposition of the urea reacts with the nitrogen oxide emissions and is converted into nitrogen and water within the catalytic converter.^ Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under 3,000 psi pressure and at 350 F. CO2 + 2NH3 > CO(NH2)2 + H2O The removal of water that occurs during the reaction is referred to as "dehydration."
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Of utmost concern to many producers in Arkansas and the rest of the U.S. is the dramatic rise in nitrogen fertilizer prices, particularly urea.
  • Nitrogen fertilizer situation and outlook 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

Other commercial uses

Laboratory uses

.Urea in concentrations up to 10 M is a powerful protein denaturant as it disrupts the noncovalent bonds in the proteins.^ The short term feeding of protein concentrates before       giving urea supplements can increase sheep's tolerance to urea ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ PEER REVIEWED**       /Urea concentrations/ from 1 to 15 mg/l for up to 14 days in river water       at   <  8 deg C exhibited negligible degradation; the same concentrations       at 4 to 6 days in river water a 20 deg C exhibited complete degradation.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

This property can be exploited to increase the solubility of some proteins. .A mixture of urea and choline chloride is used as a deep eutectic solvent, a type of ionic liquid.^ A liquid, Agrotain is used as a coating on urea.
  • Agrotain: boosting urea efficiency 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

^ Urea, methylenediurea, and dimethylenetinurea are determined by liquid       chromatography using external standards and refractive index detection.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ V1 407-9]**PEER REVIEWED**       Determination and stability studies of urea in urea creams by       high-performance liquid chromatography using a UV-spectrometer at 200 nm.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Urea can in principle serve as a hydrogen source for subsequent power generation in fuel cells.^ The aggregation was inhibited by urea,       suggesting the aggregation of red blood cells is caused by hydrogen       bonding.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Urea present in urine/wastewater can be used directly (though bacteria normally quickly degrade urea.^ One increasingly hears parents unironically addressing their children using the polite forms, even though they normally use familiar indicative forms.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ In degradation studies using estuary and coastal       waters from Georgia, avg urea degradation rates of 6.2 to 19.6 nmoles/L-hr       were observed(5); phytoplankton in the waters were responsible for the       major urea decomposition(5).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Small amounts of       urea can be released in wastewater effluents from manufacturing and use       sites(1).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

) .Producing hydrogen by electrolysis of urea solution occurs at a lower voltage (0.37v) and thus consumes less energy than the electrolysis of water (1.2v).^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ In addition, all the nitrogen is in the ammonic form and, until nitrification occurs, it is less subject to leaching or de-nitrification than the nitrate portion of the ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is safer to ship and handle, it is less corrosive to equipment, it has a higher analysis than any other dry nitrogen fertilizer and it can be used on virtually all crops.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

[5]

Medical use

.Urea is used in topical dermatological products to promote rehydration of the skin.^ Do not use any other skin products on the affected area without telling your doctor or health care professional.

^ Do not use any other skin products on the affected area without asking your doctor or health care professional.

^ My dermatologist recommended using urea cream on my arms and elbows for dry skin.
  • Topix Urix 40 Urea Cream 10 January 2010 9:24 UTC skincarerx.com [Source type: General]

.If covered by an occlusive dressing, 40% urea preparations may also be used for nonsurgical debridement of nails.^ METABOLISM    0.2.17.1 ACUTE EXPOSURE      o   WITH THERAPEUTIC USE       1.  An intolerance to carbohydrates may develop with high           urea levels.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ MUSCULOSKELETAL    0.2.15.1 ACUTE EXPOSURE      o   WITH THERAPEUTIC USE       1.  Urea is irritating to tissues.  Extravasation may lead           to pain and necrosis.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ PEER       REVIEWED**       A sterile preparation of urea (UREAPHIL) is available that may be       reconstituted for intravenous use.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

This drug is also used as an earwax removal aid.
.Certain types of instant cold packs (or ice packs) contain water and separated urea crystals.^ Urea is a white crystalline substance with the chemical formula CO(NH2)2; it is highly water soluble and contains 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is found on List D.       Case No: 4096; Pesticide type: antimicrobial; Case Status: No products       containing the pesticide are actively registered ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Rupturing the internal water bag starts an endothermic reaction and allows the pack to be used to reduce swelling.
.Like saline, urea injection is used to perform abortions.^ V1 407-9]**PEER REVIEWED**       Determination and stability studies of urea in urea creams by       high-performance liquid chromatography using a UV-spectrometer at 200 nm.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.It is also the main component of an alternative medicinal treatment referred to as urine therapy.^ The       treatment also promotes urine flow that, if maintained by fluid therapy,       may assure recovery from urea toxicosis.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.The blood urea nitrogen (BUN) test is a measure of the amount of nitrogen in the blood that comes from urea.^ Blood urea nitrogen (BUN) .
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

^ LABORATORY:   o   Follow blood urea nitrogen (BUN) to detect urea increases.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Blood urea nitrogen (BUN) and creatinine tests can be used together to find the BUN-to-creatinine ratio (BUN:creatinine).
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

.It is used as a marker of renal function.^ GENITOURINARY    0.2.10.1 ACUTE EXPOSURE      o   WITH THERAPEUTIC USE       1.  High urea levels will produce diuresis and should not           be used in patients with severely impaired renal           function.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Urea labeled with carbon-14 or carbon-13 is used in the urea breath test, which is used to detect the presence of the bacteria Helicobacter pylori (H. pylori) in the stomach and duodenum of humans, associated with ulcers.^ Prenatal testing using molecular genetic testing is available for five of the six urea cycle disorders if the disease-causing mutations have been identified in an affected family member.
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Blood urea nitrogen (BUN) and creatinine tests can be used together to find the BUN-to-creatinine ratio (BUN:creatinine).
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

^ Testing used in the diagnosis of a specific urea cycle disorder .
  • Urea Cycle Disorders Overview -- GeneReviews -- NCBI Bookshelf 10 January 2010 9:24 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

.The test detects the characteristic enzyme urease, produced by H. pylori, by a reaction that produces ammonia from urea.^ The factory using natural gas, steam and electricity to produce ammonia and from that urea and ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Ultimate urea       degradation produces ammonia and CO2 as volatile products(5).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ PEER REVIEWED**       UREA MIXED WITH SOYA MEAL IS PARTICULARLY DANGEROUS, AS UREASE IN LATTER       LEADS TO FORMATION OF AMMONIA ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

This increases the pH (reduces acidity) of the stomach environment around the bacteria. Similar bacteria species to H. pylori can be identified by the same test in animals such as apes, dogs, and cats (including big cats).

Terrorism

.Ahmed Ressam, the al-Qaeda Millenium Bomber, used urea as one of the components in the explosives that he prepared to bomb Los Angeles International Airport on New Year's Eve 1999/2000; the explosives could have produced a blast 40x greater than that of a devastating car bomb.^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The factory using natural gas, steam and electricity to produce ammonia and from that urea and ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ For his subsequent highly remunerative career as a celebrity, he was based back in Los Angeles , where he achieved greater fame as an acquitted murderer.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

[6][7]

Synthetic production

.Urea is produced on a scale of some 100,000,000 tons per year worldwide.^ But at the present time production capability is only 13,748,000 metric tons per annum.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea supplies more nitrogen per ton of product than any other dry fertilizer.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Therefore total availability for fertilizer purposes is 11,709,000 metric ton per annum.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

[8]

Industrial methods

.For use in industry, urea is produced from synthetic ammonia and carbon dioxide.^ Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under 3,000 psi pressure and at 350 F. CO2 + 2NH3 > CO(NH2)2 + H2O The removal of water that occurs during the reaction is referred to as "dehydration."
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The factory using natural gas, steam and electricity to produce ammonia and from that urea and ammonium nitrate.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ PEER REVIEWED** METHODS OF MANUFACTURING:       DEHYDRATION OF AMMONIUM CARBONATE WHICH IS SYNTHESIZED FROM AMMONIA AND       CARBON DIOXIDE. [SRI]**PEER REVIEWED**       ...
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum-derived raw materials.^ The raw material for urea and others nitrogenous fertilizers is natural gas.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under 3,000 psi pressure and at 350 F. CO2 + 2NH3 > CO(NH2)2 + H2O The removal of water that occurs during the reaction is referred to as "dehydration."
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Natural gas costs account for the majority of anhydrous ammonia production costs.
  • Nitrogen fertilizer situation and outlook 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

Such point sources of CO2 faciliate direct synthesis of urea.
The basic process, developed in 1922, is also called the Bosch-Meiser urea process after its discoverers. .The various urea processes are characterized by the conditions under which urea formation takes place and the way in which unconverted reactants are further processed.^ Urea can be practically dust-free and, under most conditions, it does not absorb moisture and cake up.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

The process consists of two main equilibrium reactions, with incomplete conversion of the reactants. The first is an exothermic reaction of liquid ammonia with dry ice to form ammonium carbamate (H2N-COONH4):[9]:
2 NH3 + CO2 ↔ H2N-COONH4 ()
The second is an endothermic decomposition of ammonium carbamate into urea and water:
H2N-COONH4 ↔ (NH2)2CO + H2O
Both reactions combined are exothermic.[8]
.Unconverted reactants can be used for the manufacture of other products, for example ammonium nitrate or sulfate, or they can be recycled for complete conversion to urea in a total-recycle process.^ Urea has over twice as much nitrogen as does ammonium sulfate; 46% versus 21%.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ There is also high demand for ammonium nitrate, which makes up 35 percent of Russia's production.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ How does urea compare with ammonium nitrate?
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

Urea can be produced as prills, granules, pellets, crystals, and solutions. Solid urea is marketed as prills or granules. .The advantage of prills is that, in general, they can be produced more cheaply than granules.^ Dehydration generally causes BUN levels to rise more than creatinine levels.
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

^ Typically, it's more efficient to generate these using a piezoelectric transducer than an electromagnetic set-up like a loudspeaker.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

Properties such as impact strength, crushing strength, and free-flowing behaviour are, in particular, important in product handling, storage, and bulk transportation. Typical impurities in the production are biuret and isocyanic acid:
2 H2CONH2 → H2CONHCONH2 + NH3
H2CONH2 → HNCO + NH3
.The biuret content is a serious concern because it is often toxic to the very plants that are to be fertilized.^ Biuret is of little concern for soil-applied nitrogen fertilizers, but it can be toxic when nitrogen fertilizers containing biuret are foliar-applied to sensitive crops such as citrus or pineapple.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

Urea is classified on the basis of its biuret content.

Laboratory processes

.Ureas in the more general sense can be accessed in the laboratory by reaction of phosgene with primary or secondary amines, proceeding through an isocyanate intermediate.^ In general, urea is rapidly       hydrolyzed to ammonium through soil urease activity(1).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Non-symmetric ureas can be accessed by reaction of primary or secondary amines with an isocyanate.

Chemical properties

Molecular and crystal structure

The urea molecule is planar. .In solid urea, the oxygen center is engaged in two N-H-O hydrogen bonds.^ The aggregation was inhibited by urea,       suggesting the aggregation of red blood cells is caused by hydrogen       bonding.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

The resulting dense and energetically favourable hydrogen-bond network is probably established at the cost of efficient molecular packing: The structure is quite open, the ribbons forming tunnels with square cross-section. The carbon in urea is described as sp2 hybridized, the C-N bonds have significant double bond character, and the carbonyl oxygen is basic compared to, say, formaldehyde. .Urea's high aqueous solubility reflects its abiltiy to engage in extensive hydrogen bonding with water.^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is a white crystalline substance with the chemical formula CO(NH2)2; it is highly water soluble and contains 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ In addition, urea is less acid forming, is more water soluble and less corrosive.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.By virtue of its tendency to form a porous frameworks, urea has the ability to trap many organic compounds.^ Urea is considered an organic compound because it contains carbon.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.In these so-called clathrates, the organic "guest" molecules are held in channels formed by interpenetrating helices comprising of hydrogen-bonded urea molecules.^ The aggregation was inhibited by urea,       suggesting the aggregation of red blood cells is caused by hydrogen       bonding.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

This behaviour can be used to separate mixtures, e.g. in the production of aviation fuel and lubricating oils, and in the separation of paraffins.
As the helices are interconnected, all helices in a crystal must have the same molecular handedness. This is determined when the crystal is nucleated and can thus be forced by seeding. The resulting crystals have been used to separate racemic mixtures.

Reactions

.Urea reacts with alcohols to form urethanes.^ V12 109       (1980)]**PEER REVIEWED**       Urea is reacted with alpha-diketones or dialdehydes to form hydantoins       [Kirk-Othmer Encyclopedia of Chemical Technology.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ V5 650 (1979)]**PEER REVIEWED**       Urea is reacted with alcohols to form alkylcarbamates [Kirk-Othmer       Encyclopedia of Chemical Technology.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

Urea reacts with malonic esters to make barbituric acids.

Safety

.Urea can be irritating to skin, eyes, and the respiratory tract.^ PEER REVIEWED** CHEMICAL SAFETY & HANDLING: SKIN, EYE AND RESPIRATORY IRRITATIONS:       Urea causes redness and irritation of skin and eyes.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ Urea may be mild to moderately irritating to the eye.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ PEER       REVIEWED** HUMAN TOXICITY VALUES:       Human, skin 22 mg/3 days intermittent, toxic effects: mild irritation       [NIOSH; Current Awareness Listing (1985)]**PEER REVIEWED** SKIN, EYE AND RESPIRATORY IRRITATIONS:       Urea causes redness and irritation of skin and eyes.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Repeated or prolonged contact with urea in fertilizer form on the skin may cause dermatitis.^ UREA (yoo REE uh) is used to soften thick, rough, or dry skin caused by certain skin conditions.

^ PEER REVIEWED** CHEMICAL SAFETY & HANDLING: SKIN, EYE AND RESPIRATORY IRRITATIONS:       Urea causes redness and irritation of skin and eyes.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

^ PEER REVIEWED** PROBABLE ROUTES OF HUMAN EXPOSURE:       Occupational exposure to urea occurs through dermal contact and inhalation       of dust, especially to workers applying urea fertilizers(1).
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.High concentrations in the blood can be damaging.^ Kidney damage can be caused by diabetes or high blood pressure that directly affect the kidneys.
  • Health Information 10 January 2010 9:24 UTC www.mmc.org [Source type: Academic]

^ HEENT    0.2.4.1 ACUTE EXPOSURE      o   WITH POISONING/EXPOSURE       1.  Eye damage is expected only when concentrations are           high or duration of exposure is extended .  Rebound           increases in intraocular pressure  have been seen.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Ingestion of low concentrations of urea, such as are found in typical human urine, are not dangerous with additional water ingestion within a reasonable time-frame.^ When it was founded (as the ``Department of History of Science'') in 1956 or 1957, it was the first such department in North America (as opposed to interdisciplinary programs, typically based in history departments).
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ In addition, urea is less acid forming, is more water soluble and less corrosive.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ PEER REVIEWED**       /Urea concentrations/ from 1 to 15 mg/l for up to 14 days in river water       at   <  8 deg C exhibited negligible degradation; the same concentrations       at 4 to 6 days in river water a 20 deg C exhibited complete degradation.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Many animals (e.g., dogs) have a much more concentrated urine and it contains a higher urea amount than normal human urine; this can prove dangerous as a source of liquids for consumption in a life-threatening situation (such as in a desert).^ Urea contains about one-third more nitrogen, is less corrosive than ammonium nitrate and is less prone to caking.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea supplies more nitrogen per ton of product than any other dry fertilizer.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ PEER REVIEWED** ENVIRONMENTAL FATE & EXPOSURE: ENVIRONMENTAL FATE/EXPOSURE SUMMARY:       Urea occurs naturally in urine and animal waste and can be formed       naturally in the environment through protein metabolism.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

.Urea can cause algal blooms to produce toxins, and its presence in the runoff from fertilized land may play a role in the increase of toxic blooms.^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ These may be attributed to the increases of microbial populations caused by supplemented nutrients.
  • Effect of urea 10 January 2010 9:24 UTC www.mekarn.org [Source type: Academic]

^ What role does urea play in world commerce?
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

[10]
.The substance decomposes on heating above melting point, producing toxic gases, and reacts violently with strong oxidants, nitrites, inorganic chlorides, chlorites and perchlorates, causing fire and explosion.^ PEER REVIEWED** HAZARDOUS REACTIVITIES & INCOMPATIBILITIES:       REACTS VIOLENTLY WITH GALLIUM PERCHLORATE. [Sax, N.I. Dangerous Properties       of Industrial Materials.
  • Urea CAS Nr 57-13-6 as Used in Inipol EAP 22 10 January 2010 9:24 UTC www.valdezhousing.com [Source type: Academic]

[citation needed]

References

  1. ^ Williams, R. (2001-10-24). "pKa Data". http://research.chem.psu.edu/brpgroup/pKa_compilation.pdf. Retrieved 2009-11-27. 
  2. ^ Nicolaou, Kyriacos Costa; Tamsyn Montagnon (2008). Molecules That Changed The World. Wiley-VCH. pp. 11. ISBN 978-3-527-30983-2. 
  3. ^ Sakami W, Harrington H (1963). "Amino acid metabolism". Annual Review of Biochemistry 32: 355–98. doi:10.1146/annurev.bi.32.070163.002035. PMID 14144484. 
  4. ^ Walter F. Boron. Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3.  Page 837
  5. ^ Researchers develop urea fuel cell.
  6. ^ U.S. Court of Appeals for the Ninth Circuit (February 2, 2010). "U.S. v. Ressam". http://www.nefafoundation.org/miscellaneous/US_v_Ressam_9thcircuitappeals0210.pdf. Retrieved February 27, 2010. 
  7. ^ "Complaint; U.S. v. Ressam". NEFA Foundation. December 1999. http://nefafoundation.org/miscellaneous/FeaturedDocs/U.S._v_Ressam_Complaint.pdf. Retrieved February 26, 2010. 
  8. ^ a b Jozef H. Meessen and Harro Petersen “Urea” in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a27_333
  9. ^ http://www.hillakomem.com/tag/ammonium-carbamate
  10. ^ newscientist.com - US set to track toxic algal blooms

External links


1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

.UREA, or Carbamide, Co(NH2)2, the amide of carbonic acid, discovered in 1773 by H. M. v.^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Chemically it is carbamide, CO(NH2)2 , and when heated with strong acids or alkalies is decomposed into carbonic acid and ammonia.

^ Urea was first discovered in human urine by H.M. Rouelle in 1773 .
  • Urea 10 January 2010 9:24 UTC www.3rd1000.com [Source type: Reference]
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

.Rouelle, is found in the urine of mammalia, birds and some reptiles; human urine contains approximately 2-3%, a grown man producing about 30 grammes daily.^ It is the main product of the regressive metamorphosis (katabolism) of proteid matter in the body, and is excreted daily to the amount of about 500 grains by a man of average weight.
  • Urea@Everything2.com 10 January 2010 9:24 UTC www.everything2.com [Source type: FILTERED WITH BAYES]

^ CO(NH), found in the urine and other body fluids of mammals or produced synthetically: used in making plastics, fertilizer, adhesives, etc.
  • urea - Definition of urea at YourDictionary.com 10 January 2010 9:24 UTC www.yourdictionary.com [Source type: General]

^ It was first discovered and isolated from human urine by H.M. Rouelle in 1773, and was then successfully synthesised in 1828 by Friedrich Wohler.

.It is also a constituent of the blood, of milk, and other animal fluids.^ It is also a constituent of the blood, of milk , and other animal fluids.

^ In lesser quantities, it is present in the blood, liver, lymph, and serous fluids and is found in the excrement of fish and many other lower animals.

^ The biological fluid can be an extract, as from a tissue homogenate or the like, or it can be an animal body fluid such as blood, plasma, serum, urine, lymphatic fluid, bile, cerebrospinal fluids or the like.
  • Urea determination of biological fluids using diacetylmonoxime reaction - Patent 4040787 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Academic]

.Its synthesis in 1828 by F. Wohler (Pogg.^ Its synthesis in 1828 by F. Wohler ( Pogg.

.Ann.,
1828, 12, p.^ Ann., 1828, 12, p.

.253) is of theoretical importance, since it was the first organic compound obtained from inorganic materials.^ It was synthesised in 1828 by Friedrich Wohler and was the first organic compound to be synthesised from inorganic starting materials.
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

^ It was synthesized in 1828 by Friedrich Wohler and was the first organic compound to be synthesized from inorganic starting materials.

^ It was the first organic chemical compound ever synthesized.
  • Urea definition - Medical Dictionary definitions of popular medical terms easily defined on MedTerms 10 January 2010 9:24 UTC www.medterms.com [Source type: FILTERED WITH BAYES]

.Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r-->K CNO--->NH4CNO->CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane; by heating ammonium carbamate in a sealed tube to 130-140° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E. Baudrimant, Jahresb., 1880, p.^ Acid potassium permanganate oxidizes it to carbon dioxide and nitrogen.

^ Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r--> K CNO---> NH4CNO-> CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane ; by heating ammonium carbamate in a sealed tube to 130-140° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E. Baudrimant, Jahresb., 1880, p.

^ Ammonium carbamate is obtained by direct reaction of ammonia with carbon dioxide.
  • Urea 10 January 2010 9:24 UTC www.3rd1000.com [Source type: Reference]
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

.393); by the action of 50% sulphuric acid on cyanamide: CN NH2+H20= CO(NH 2) 2; by the action of mercuric oxide on oxamide (A. Williamson): (CONH 2) 2 +HgO= CO(NH2)2+ Hg +CO 2 j by decomposing potassium cyanide with a dilute solution of sodium hypochlorite, followed by adding ammonium sulphate (A. Reychler, Bull.^ CN NH2+H20= CO(NH 2) 2; by the action of mercuric oxide on oxamide (A. Williamson): (CONH 2) 2 +HgO= CO(NH2)2+ Hg +CO 2 j by decomposing potassium cyanide with a dilute solution of sodium hypochlorite, followed by adding ammonium sulphate (A. Reychler, Bull.

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Wdhler oxidized potassium ferrocyanide to potassium cyanate by fusing it with lead or manganese dioxide, converted this cyanate into ammonium cyanate by adding ammonium sulphate, and this on evaporation gives urea, thus: K 4 Fe(NC)r--> K CNO---> NH4CNO-> CO (NH2)2 It may also be prepared by the action of ammonia on carbonyl chloride, diethyl carbonate, chlorcarbonic ester or urethane ; by heating ammonium carbamate in a sealed tube to 130-140° C.; by oxidizing potassium cyanide in acid solution with potassium permanganate (E. Baudrimant, Jahresb., 1880, p.

Soc. .Chinn.,
18 93 [3], 9, p.^ Chinn., 18 93 [3], 9, p.

427); and by oxidation of uric acid. .It may be obtained from urine by evaporating to dryness on the water bath, taking up the residue in absolute alcohol and evaporating the alcoholic solution to dryness again.^ It may be obtained from urine by evaporating to dryness on the water bath , taking up the residue in absolute alcohol and evaporating the alcoholic solution to dryness again.

^ The solution is then evaporated to dryness and extracted by alcohol.

^ On treating silver cyanate with ammonium chloride solution he obtained a white crystalline material which proved identical to urea obtained from urine.
  • Urea 10 January 2010 9:24 UTC www.3rd1000.com [Source type: Reference]
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

.The residue is then dissolved in water, decolorized by animal charcoal and saturated at 50 C. with oxalic acid.^ The residue is then dissolved in water, decolorized by animal charcoal and saturated at 50 C. with oxalic acid .

^ Therefore, urea is more beneficially administered as part of molasses-urea mixture rather than being dissolved in water and sprinkled onto a cereal crop residue.
  • Effects of urea, molasses, molasses-urea, noug cake and legume hay on the intake and digestibility of teff straw by highland sheep 10 January 2010 9:24 UTC www.fao.org [Source type: Academic]

^ Dissolve urea in water at a 50:50 ratio, and apply as a spray at the end of the day to reduce the risk of leaf burn by the urea.

.The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J. J. Berzelius, Pogg.^ The urea oxalate is recrystallized and decolorized and finally decomposed by calcium carbonate (J. J. Berzelius, Pogg.

^ Urea is the chief nitrogenous constituent of urine and, along with carbon dioxide, the final product of protein metabolism in the body.
  • Taber's Medical Dictionary:urea 10 January 2010 9:24 UTC www.tabers.com [Source type: Reference]

^ Alkaline hypobromites or hypochlorites or nitrous acid decompose urea into carbon dioxide and nitrogen.

.Ann.,
1830, 18, p.^ Ann., 1830, 18, p.

84). .As an alternative method, A. N. E. Millon (Ann.^ As an alternative method, A. N. E. Millon ( Ann.

chim. phys [2],
8, p. .235) concentrates the urine and precipitates the urea by nitric acid.^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ Urea nitrate is a crystalline substance, made by mixing urea and nitric acid.
  • Amazon.com: "urea nitrate": Key Phrase page 10 January 2010 9:24 UTC www.amazon.com [Source type: General]

.The precipitate is dissolved in boiling water, decolorized by potassium permanganate and decomposed by barium carbonate.^ The precipitate is dissolved in boiling water, decolorized by potassium permanganate and decomposed by barium carbonate.

^ Acid potassium permanganate oxidizes it to carbon dioxide and nitrogen.

^ The residue is then dissolved in water, decolorized by animal charcoal and saturated at 50 C. with oxalic acid .

.The solution is then evaporated to dryness and extracted by alcohol.^ The solution is then evaporated to dryness and extracted by alcohol.

^ It may be obtained from urine by evaporating to dryness on the water bath , taking up the residue in absolute alcohol and evaporating the alcoholic solution to dryness again.

.Urea crystallizes in long needles or prisms which melt at 132° C. and sublime when heated in vacuo. It is readily soluble in water and in alcohol, but is insoluble in chloroform and ether.^ Urea is also highly water soluble so it moves readily into the soil.
  • Allied World Resources - Urea 10 January 2010 9:24 UTC www.alliedworldresources.com [Source type: Reference]
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ It crystallizes in needles and is readily hydrolysed by alkalis.

^ It crystallizes in needles which melt at 190° C. (with decomposition), and is readily soluble in hot water.

.When heated above its melting-point, it yields ammonia, cyanuric acid, biuret and ammelide.^ When heated above its melting-point, it yields ammonia, cyanuric acid, biuret and ammelide.

^ When heated strongly it is decomposed into ammonia and cyanuric acid.

^ They are readily decomposed by alkalis, yielding cyanuric acid and ammonia.

.On warming with sodium, it yields cyanamide.^ On warming with sodium, it yields cyanamide.

.Dry chlorine gas passed into melted urea decomposes it with formation of cyanuric acid and ammonium chloride, nitrogen and ammonia being simultaneously liberated.^ Instead, it turns the nitrogen into ammonia.
  • Urea Cycle Disorder - Associated Content - associatedcontent.com 10 January 2010 9:24 UTC www.associatedcontent.com [Source type: General]
  • Kaiser Permanente Genetics Northern California 10 January 2010 9:24 UTC mydoctor.kaiserpermanente.org [Source type: FILTERED WITH BAYES]

^ When heated strongly it is decomposed into ammonia and cyanuric acid.

^ Dry chlorine gas passed into melted urea decomposes it with formation of cyanuric acid and ammonium chloride, nitrogen and ammonia being simultaneously liberated.

.Alkaline hypobromites or hypochlorites or nitrous acid decompose urea into carbon dioxide and nitrogen.^ It causes urea to take up water and decompose into carbonic acid and ammonia.
  • Urea@Everything2.com 10 January 2010 9:24 UTC www.everything2.com [Source type: FILTERED WITH BAYES]

^ This enzyme hydrolyzes urea into ammonia, water and carbon dioxide.

^ The reaction involves condensation between the nucleophilic nitrogen of urea with the electrophilic carbonyl carbon of formaldehyde.
  • Urea-Formaldehyde Resin 10 January 2010 9:24 UTC jchemed.chem.wisc.edu [Source type: FILTERED WITH BAYES]

.It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.^ It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.

^ Hydrolysis by alkalis decomposes them into carbon dioxide, amines and ammonia.

^ It is hydrolysed by alkalis, giving carbon dioxide, ammonia and sulphuretted hydrogen.

.When heated with alcohol in sealed tubes, it yields carbamic esters; with alcohol and carbon bisulphide at Ioo° C., carbon dioxide is liberated and ammonium sulphocyanide is formed.^ Ammonium carbamate is obtained by direct reaction of ammonia with carbon dioxide.
  • Urea 10 January 2010 9:24 UTC www.3rd1000.com [Source type: Reference]
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

^ In 1870 urea was produced by heating ammonium carbamate in a sealed vessel.
  • Urea 10 January 2010 9:24 UTC www.3rd1000.com [Source type: Reference]
  • Molecule of the Month - UREA - [57-13-6] 10 January 2010 9:24 UTC www.chm.bris.ac.uk [Source type: Reference]

^ When heated with alcohol in sealed tubes, it yields carbamic esters ; with alcohol and carbon bisulphide at Ioo° C., carbon dioxide is liberated and ammonium sulphocyanide is formed.

.Acid potassium permanganate oxidizes it to carbon dioxide and nitrogen.^ Acid potassium permanganate oxidizes it to carbon dioxide and nitrogen.

^ A synthetic organic compound produced by the reaction of ammonia with carbon dioxide, urea is the solid nitrogenous fertilizer with the highest nitrogen content (46%).
  • Welcome to PIC | We pave the way for better future 10 January 2010 9:24 UTC www.pic.com.kw [Source type: Reference]

^ Carbon dioxide generated during the reaction reacts with potassium hydroxide in the solution to form potassium carbonate.
  • Green Car Congress: Researchers Develop Urea Electrolysis for Conversion of Urine and Urea to Hydrogen 10 January 2010 9:24 UTC www.greencarcongress.com [Source type: FILTERED WITH BAYES]

It acts as a monacid base. .Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ Biuret is formed during the manufacturing of urea.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ From urea and ammonium nitrate the factory produces UAN Solution; .
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

.In this reaction urea is heated in a dry tube until it gives off ammonia freely; the residue is dissolved in water, made alkaline with caustic soda, and a drop of copper sulphate solution is added, when a fine violet-red coloration is produced.^ By contrast, ammonia or ammonia compounds give off a very strong ammonia odor in water solutions.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ Urea must be kept dry, for when water combines with Urea it gives off ammonia and becomes ineffective.

^ In this reaction urea is heated in a dry tube until it gives off ammonia freely; the residue is dissolved in water, made alkaline with caustic soda, and a drop of copper sulphate solution is added, when a fine violet -red coloration is produced.

.Several methods are employed for the quantitative estimation of urea.^ Several methods are employed for the quantitative estimation of urea.

^ When rigorously performed, formal UKM is a reproducible, quantitative method that has several advantages for assessing the adequacy of hemodialysis.
  • NKF KDOQI Guidelines 10 January 2010 9:24 UTC www.kidney.org [Source type: Academic]

^ Numerous reagents have been employed in methods for the determination of urea or urea nitrogen in biological fluids such as serum, plasma, urine, or the like.
  • Urea determination of biological fluids using diacetylmonoxime reaction - Patent 4040787 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Academic]

R. Bunsen (Ann., 1848, 6 5, p. .8 75) heated urea with an ammoniacal solution of barium chloride to 220° C., and converted the barium carbonate formed into barium sulphate, which is then weighed (see also E. Pfluger and K. Bohland, Zeit.^ Chlorides also prevent the formation of the precipitate until enough of the mercury solution has been added to convert them into mercuric chloride (see also E. Pfluger, Zeit.

^ C., and converted the barium carbonate formed into barium sulphate, which is then weighed (see also E. Pfluger and K. Bohland, Zeit.

^ Urea is produced by converting ammonia and carbon dioxide under chemical process to become solid urea in the form of prill (size 1-3,35 mm) or granular (size 2-4,75 mm), both are produced by Pupuk Kaltim.

f. anal. Chem.,
1886, 2 5, p. .599; K. A. H. Morner, ibid., 1891, 30, p.^ K. A. H. Morner, ibid., 1891, 30, p.

389). .Among the volumetric methods used, the one most commonly employed is that of W. Knop (ibid., 1870, 9, p.^ It is most commonly used to promote late autumn and early spring growth.

^ Still, the PEG is one of the most useful valuation measures in an investor's tool kit, particularly when comparing one company with another.
  • Urea! at SmartMoney.com 10 January 2010 9:24 UTC www.smartmoney.com [Source type: General]

^ Conclusions UFFI is one of the most thoroughly investigated, and most innocuous building products we have used.

.226), in which the urea is decomposed by an alkaline hypobromite and the evolved nitrogen is measured (see A. H. Allen, Commercial Organic Analysis). J. v.^ Clinical diagnosis See blood urea nitrogen ("BUN") for a commonly performed urea test, and marker of renal function .
  • Urea.eu 10 January 2010 9:24 UTC www.urea.eu [Source type: Reference]
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ The concentration of urea nitrogen in the sample is then determined by measuring the depth or intensity of the color, usually with a colorimeter or a spectro-photometer.
  • Urea determination of biological fluids using diacetylmonoxime reaction - Patent 4040787 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Academic]

^ Blood urea nitrogen is most accurately measured by a colorimetric process, which gives a quantitative test result.
  • Blood Urea Nitrogen (BUN) Concentration in Dogs 10 January 2010 9:24 UTC www.vet.uga.edu [Source type: Academic]

.Liebig (Ann., 18 53, 8 5, p.^ Liebig ( Ann., 18 53, 8 5, p.

.289) precipitates dilute solutions of urea with a dilute standard solution of mercuric nitrate, using alkaline carbonate as indicator.^ Urea-ammonium nitrate solution - UAN .
  • Zak�ady Azotowe Pu�awy - Urea 10 January 2010 9:24 UTC www.zapulawy.pl [Source type: FILTERED WITH BAYES]

^ Nitrogen Solutions Urea is used in the manufacture of nitrogen solutions.
  • AGR-69 UREA AS A SOURCE OF FERTILIZER NITROGEN FOR CROPS IN KENTUCKY 10 January 2010 9:24 UTC www.ca.uky.edu [Source type: Academic]

^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

.In this process phosphates must be absent, and the nitric acid liberated during the reaction should be neutralized as soon as possible.^ In this process phosphates must be absent, and the nitric acid liberated during the reaction should be neutralized as soon as possible.

^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ During summer, urea should be spread just before, or during rain to reduce possible losses from volatilisation (process where nitrogen is lost to the atmosphere as ammonia gas).
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

.Chlorides also prevent the formation of the precipitate until enough of the mercury solution has been added to convert them into mercuric chloride (see also E. Pfluger, Zeit.^ Chlorides also prevent the formation of the precipitate until enough of the mercury solution has been added to convert them into mercuric chloride (see also E. Pfluger, Zeit.

^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ A urea solution (AUS32 or AdBlue) is sprayed into the engine’s exhaust fumes where it converts the nitrogen oxides to nitrogen and water.
  • Urea Uses and Market Data 10 January 2010 9:24 UTC www.icis.com [Source type: News]

f. anal. Chem.,
1880, 1 9, p. 378). .E. Riegler (ibid., 18 94, 33, p.^ E. Riegler (ibid., 18 94, 33, p.

.49) decomposes urea solutions by means of mercury dissolved in nitric acid, and measures the evolved gas.^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid.
  • Urea Breath Test Glossary of Terms with Definitions on MedicineNet.com 10 January 2010 9:24 UTC www.medicinenet.com [Source type: FILTERED WITH BAYES]

^ As a practical guide, when preparing urea solutions for fertigation (injection into irrigation lines), dissolve nomore than 30 kg urea per 100 L water.

.Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines.^ Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines .

^ Chemically, the urine is mainly an aqueous (watery) solution of salt (sodium chloride) and substances called urea and uric acid.
  • Urea Breath Test Glossary of Terms with Definitions on MedicineNet.com 10 January 2010 9:24 UTC www.medicinenet.com [Source type: FILTERED WITH BAYES]

^ These two materials are combined under high pressures and elevated temperatures to form ammonium carbamate, which then decomposes at much lower pressures to yield urea and water.
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

.They are readily hydrolysed by water, and combine with bases to form alkyl ureas, and with alcohols to form carbamic esters.^ Urea reacts with alcohols to form urethanes.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

^ They are readily hydrolysed by water, and combine with bases to form alkyl ureas, and with alcohols to form carbamic esters.

^ The commercial synthesis of urea is a by-product of the petro-chemical industry and involves the combination of ammonia and carbon dioxide at high pressure to form ammonium carbamate which is subsequently dehydrated by the application of heat to form urea and water.
  • Urea and Molasses-Urea blocks 10 January 2010 9:24 UTC www.smallstock.info [Source type: FILTERED WITH BAYES]

.Substituted urea chlorides are formed by the direct action of chlorine (F. D. Chattaway and D. F. S. Wunsch, Jour.^ Substituted urea chlorides are formed by the direct action of chlorine (F. D. Chattaway and D. F. S. Wunsch, Jour.

^ Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.

^ Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.

Chem. .Soc.,
1909, 95, p.^ Soc., 1909, 95, p.

129). .Urea chloride, NH 2 CO C1 (L. Gattermann, Ann., 1888, 244, p.^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea (NH 2 -CO-NH 2 , 46.7% N) is a useful cheap source of non-protein nitrogen for ruminants, in which 100 g urea is equivalent to 220 g digestible crude protein.
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]

^ Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.

.30), melts at 50° C. and boils at 61-62° C. In the presence of anhydrous aluminium chloride it reacts with aromatic hydrocarbons to form the amides of aromatic acids.^ C. and boils at 61-62° C. In the presence of anhydrous aluminium chloride it reacts with aromatic hydrocarbons to form the amides of aromatic acids.

^ Those containing more than one acyl group are formed by the action of carbonyl chloride on acid amides : COC1 2 +2CH 3 Conh 2 = Co (NHCOCH3)2+2HC1.

^ Urea reacts with alcohols to form urethanes and with malonic esters to give barbituric acids .
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

.Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea may be recognized by its crystalline oxalate and nitrate, which are produced on adding oxalic and nitric acids to concentrated solutions of the base; by the white precipitate formed on adding mercuric nitrate to the neutral aqueous solutions of urea; and by the so-called "biuret" reaction.

^ Under action of concentrated sulfuric acid or other dehydrating agents it yields nitrourea, which is a more powerful explosive than urea nitrate.
  • .aware gamma zine - Improvised Urea Nitrate 10 January 2010 9:24 UTC www.awarenetwork.org [Source type: FILTERED WITH BAYES]

.281), is a crystalline powder, soluble in water, and which decomposes on heating.^ Urea is a white crystalline substance with the chemical formula CO(NH2)2; it is highly water soluble and contains 46% nitrogen.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ When heated with water it is decomposed into carbon dioxide, ammonia, methylamine and acetic acid .

.It is a strong acid and is stable towards oxidizing agents.^ It is a strong acid and is stable towards oxidizing agents.

^ Incompatibilities with Other Materials: Strong oxidizing agents, sodium hypochlorite, sodium nitrate, calcium hypochlorite, nitrosyl perchlorate, gallium perchlorate, diphosphorus pentachloride.

.Diazomethane converts it into the methyl derivatives of isocyanic acid, and nitramide, NH2N02. Amidourea, or semicarbazide, NH 2 CO NH NH 2, is best prepared from hydrazine sulphate and potassium cyanate (J. Thiele and 0. Stange, Ber., 18 94, 2 7, p.^ Amidourea, or semicarbazide, NH 2 CO NH NH 2, is best prepared from hydrazine sulphate and potassium cyanate (J. Thiele and 0.

^ Diazomethane converts it into the methyl derivatives of isocyanic acid, and nitramide, NH2N02.

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

31). .It may also be obtained by reducing nitrourea in acid solution with zinc dust.^ It may also be obtained by reducing nitrourea in acid solution with zinc dust .

^ It may be obtained from urine by evaporating to dryness on the water bath , taking up the residue in absolute alcohol and evaporating the alcoholic solution to dryness again.

.It crystallizes in prisms, which melt at 96° C., and are easily soluble in water.^ It crystallizes in thick prisms which melt at 180° C. and is readily soluble in water.

^ It crystallizes in prisms, which melt at 96° C., and are easily soluble in water.

^ Basically, all you need is to have 1 mol of nitrate ions from AN. KNO3 is less soluble in water, but more easily available in many places than NH4NO3.
  • .aware gamma zine - Improvised Urea Nitrate 10 January 2010 9:24 UTC www.awarenetwork.org [Source type: FILTERED WITH BAYES]

.It reduces Fehling's solution in the cold.^ It reduces Fehling's solution in the cold.

.It reacts with carbonyl compounds, giving semi-carbazones, and in consequence is frequently used for characterizing such substances.^ It reacts with carbonyl compounds, giving semi-carbazones, and in consequence is frequently used for characterizing such substances.

^ With certain straight-chain aliphatic hydrocarbons and their derivatives, urea forms crystalline inclusion compounds, which are useful for purifying the included substances.
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

^ If the body really does produce such an amazing substance, and doctors and scientists have used it to heal people, where are the news reports, the accolades, the commercials, the media hype?

.Hydroxy-urea, N H2 CO NH OH, is produced from hydroxylamine and cyanic acid (W. F. Dresler and R. Stein, Ann., 1869, 150, p.^ The first reaction (2NH 3 + CO 2 --> H 2 N-CO-NH 3 OH (ammonium carbamate)) is exothermic and the second reaction (H 2 N-CO-NH 3 OH (ammonium carbamate) --> H 2 N-CO-NH 2 + H 2 O) is endothermic.
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea (NH 2 -CO-NH 2 , 46.7% N) is a useful cheap source of non-protein nitrogen for ruminants, in which 100 g urea is equivalent to 220 g digestible crude protein.
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]

.242), or from ammonium hypochlorite and potassium cyanate (A. Hantzsch, Ann., 1898, 299, p.^ It was the first organic compound to be artificially synthesized from inorganic starting materials, in 1828 by Friedrich Wöhler , who prepared it by the reaction of potassium cyanate with ammonium sulfate .

^ It was the first organic compound to be artificially synthesised in 1828 by Friedrich Woehler, who prepared it by the reaction of potassium cyanate with ammonium sulfate.
  • Urea - The Doctors Lounge(TM) 10 January 2010 9:24 UTC www.doctorslounge.com [Source type: FILTERED WITH BAYES]

^ It was the first organic compound to be artificially synthesized from inorganic starting materials, in 1828 by Friedrich Woehler , who prepared it by the reaction of potassium cyanate with ammonium sulfate .
  • Urea.eu 10 January 2010 9:24 UTC www.urea.eu [Source type: Reference]
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]

99). .It crystallizes in needles, which melt at 128-130° C., and is decomposed on long heating.^ The substance decomposes on heating above melting point producing toxic gases.

.It is readily soluble in water and reduces warm silver solutions.^ Urea is also highly water soluble so it moves readily into the soil.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions (in combination with ammonium nitrate : UAN ), e.g.
  • Urea.eu 10 January 2010 9:24 UTC www.urea.eu [Source type: Reference]
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]
  • Urea 10 January 2010 9:24 UTC human.freescience.org [Source type: Reference]

^ Reaction with Soil In its chemical form, urea is unreactive with soil and is readily soluble in water.
  • AGR-69 UREA AS A SOURCE OF FERTILIZER NITROGEN FOR CROPS IN KENTUCKY 10 January 2010 9:24 UTC www.ca.uky.edu [Source type: Academic]

.Hyponitrous acid is formed by passing nitrous fumes into its methyl alcohol solution.^ Hyponitrous acid is formed by passing nitrous fumes into its methyl alcohol solution.

^ Urea reacts with alcohols to form urethanes and with malonic esters to give barbituric acids .
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

^ A urea solution (AUS32 or AdBlue) is sprayed into the engine’s exhaust fumes where it converts the nitrogen oxides to nitrogen and water.
  • Urea Uses and Market Data 10 January 2010 9:24 UTC www.icis.com [Source type: News]

.Alkyl ureas are formed by the action of primary or secondary amines on isocyanic acid or its esters: [[Conh+Nh2r= R Nhc0nh]] 2 i [[Conr+Nhr 2 =Nr 2 Co Nhr]]; by the action of carbonyl chloride on amines: COC12+2NHR2=C0(NR2)2+2HC1; and in the hydrolysis of many ureides.^ Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines .

^ The catalytic hydrolysis of isocyanic acid (HNCO) in the urea-SCR process .

^ Alkyl ureas are formed by the action of primary or secondary amines on isocyanic acid or its esters: [[Conh+Nh2r= R Nhc0nh]] 2 i [[Conr+Nhr 2 =Nr 2 Co Nhr]]; by the action of carbonyl chloride on amines: COC12+2NHR2=C0(NR2)2+2HC1; and in the hydrolysis of many ureides.

.The tetra-alkyl derivatives are liquids, the remainder being solids.^ The tetra-alkyl derivatives are liquids, the remainder being solids.

.Hydrolysis by alkalis decomposes them into carbon dioxide, amines and ammonia.^ It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.

^ Hydrolysis by alkalis decomposes them into carbon dioxide, amines and ammonia.

^ When heated with water it is decomposed into carbon dioxide, ammonia, methylamine and acetic acid .

.The symmetrically substituted ureas are generally tasteless, while the asymmetrical derivatives are sweet.^ The symmetrically substituted ureas are generally tasteless, while the asymmetrical derivatives are sweet.

^ For example, aa -dimethyl urea is sweet, aß-dimethyl urea is tasteless; p-phenetol carbamide or dulcin, NH 2 CO NH C 6 H 4.0C 2 H 51 is sweet, while the di-p-phenetol carbamide, CO(NH C 6 H 4.0C 2 H 5) 21 is tasteless.

^ These products generally have been found to be less satisfactory than urea as a protein substitute.
  • Urea and NPN for Cattle and Sheep 10 January 2010 9:24 UTC www.ext.colostate.edu [Source type: FILTERED WITH BAYES]

.For example, aa-dimethyl urea is sweet, aß-dimethyl urea is tasteless; p-phenetol carbamide or dulcin, NH 2 CO NH C 6 H 4.0C 2 H 51 is sweet, while the di-p-phenetol carbamide, CO(NH C 6 H 4.0C 2 H 5) 21 is tasteless.^ For example, aa -dimethyl urea is sweet, aß-dimethyl urea is tasteless; p-phenetol carbamide or dulcin, NH 2 CO NH C 6 H 4.0C 2 H 51 is sweet, while the di-p-phenetol carbamide, CO(NH C 6 H 4.0C 2 H 5) 21 is tasteless.

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

.The derivatives of urea containing acid radicles are known as ureides. Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.^ It behaves as a monobasic acid and forms unstable salts.

^ The derivatives of urea containing acid radicles are known as ureides.

^ Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.

Those containing more than one acyl group are formed by the action of carbonyl chloride on acid amides: COC1 2 +2CH 3 Conh 2 = Co(NHCOCH3)2+2HC1.
.Acetyl urea, NH 2 CO NH 000H 31 formed by the action of acetic anhydride on urea, crystallizes in needles which melt at 212° C. and, on heating, strongly decomposes into acetamide and cyanuric acid.^ Urea was the first animal metabolite to be isolated in crystalline form; its crystallization was described in the early 18th cent., and in 1773 it was noted that urea gave off ammonia when heated.
  • urea Facts, information, pictures | Encyclopedia.com articles about urea 10 January 2010 9:24 UTC www.encyclopedia.com [Source type: Academic]

^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ Urea (NH 2 -CO-NH 2 , 46.7% N) is a useful cheap source of non-protein nitrogen for ruminants, in which 100 g urea is equivalent to 220 g digestible crude protein.
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]

.Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ Urea (NH 2 -CO-NH 2 , 46.7% N) is a useful cheap source of non-protein nitrogen for ruminants, in which 100 g urea is equivalent to 220 g digestible crude protein.
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]

^ It is most important to note that both the hydroxide and carbamate forms of ammonia produce significantly less byproduct N 2 O and less increased CO compared with urea.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

) and acetamide (2 mols.) (A. W. v. .Hofmann, Ber., 1881, 14, p.^ Hofmann, Ber., 1881, 14, p.

2725), or of methylamine on acetylurethane (G. Young, Jour. Chem. .Soc., 18 9 8, 73, p.^ Soc., 18 9 8, 73, p.

364). .When heated with water it is decomposed into carbon dioxide, ammonia, methylamine and acetic acid.^ Acetic acid furnished by the vinegar lowers rumen pH and neutralizes ammonia, thus preventing further absorption of ammonia into the bloodstream.
  • Urea and NPN for Cattle and Sheep 10 January 2010 9:24 UTC www.ext.colostate.edu [Source type: FILTERED WITH BAYES]

^ Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under 3,000 psi pressure and at 350 F. CO2 + 2NH3 > CO(NH2)2 + H2O The removal of water that occurs during the reaction is referred to as "dehydration."
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Physiologically, urea is synthesized from ammonia and carbon dioxide.
  • Team:NYMU-Taipei/Project/Urea - 2008.igem.org 10 January 2010 9:24 UTC 2008.igem.org [Source type: Academic]

.Bromural or a-bromisovaleryl urea, NH 2 C0 NH C0 CHBr CH(CH 3) 2, has been introduced as an hypnotic; its action is mild, and interfered with by the presence of pain, cough or delirium.^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ Ureas cure by chemical action in which the presence of water is necessary.
  • How to Use Powdered Urea Resin Adhesives 10 January 2010 9:24 UTC cpadhesives.com [Source type: FILTERED WITH BAYES]

.The ureides of oxy-acids and dibasic acids form closed chain compounds (see Allantoin; Alloxan; Hydantoin; Purin).^ The ureides of oxy-acids and dibasic acids form closed chain compounds (see Allantoin ; Alloxan ; Hydantoin ; Purin ).

^ With certain straight-chain aliphatic hydrocarbons and their derivatives, urea forms crystalline inclusion compounds, which are useful for purifying the included substances.
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

^ Example of ureas are the compounds carbamide peroxide , allantoin and Hydantoin .
  • Urea.eu 10 January 2010 9:24 UTC www.urea.eu [Source type: Reference]
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]
  • Urea 10 January 2010 9:24 UTC human.freescience.org [Source type: Reference]

.Parabanic acid (oxalyl urea), C0[NH C0] 21 is formed by oxidizing uric acid; or by condensing oxalic acid and urea in the presence of phosphorus oxychloride.^ In aquatic organisms the most common form of nitrogen waste is ammonia, while land-dwelling organisms developed ways to convert the toxic ammonia to either urea or uric acid .
  • Urea.eu 10 January 2010 9:24 UTC www.urea.eu [Source type: Reference]

^ In aquatic organisms the most common form of nitrogen waste is ammonia , while land-dwelling organisms developed ways to convert the toxic ammonia to either urea or uric acid .
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]

^ Urea [ CO(NH 2 ) 2 -- di amino methanal] is an organic substance produced in the liver and known from its presence in urine.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

It crystallizes in needles and is readily hydrolysed by alkalis. .It behaves as a monobasic acid and forms unstable salts.^ It behaves as a monobasic acid and forms unstable salts.

^ It acts as a weak base and forms salts with one equivalent of an acid.

^ Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.

.When heated with urea, it forms oxalyl diureide, H 2 N [[Coco.^ When heated with urea, it forms oxalyl diureide, H 2 N [[Coco.

^ Parabanic acid (oxalyl urea), C0[NH C0] 21 is formed by oxidizing uric acid; or by condensing oxalic acid and urea in the presence of phosphorus oxychloride.

^ When urea is heated with diacetylmonoxime in the presence of a strong acid such as sulfuric, phosphoric, hydrochloric, or nitric a chromophor is formed having an absorption peak at 480 nm.
  • Urea determination of biological fluids using diacetylmonoxime reaction - Patent 4040787 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Academic]

Nh Co. .Nh Conh]] 2. Dimethylparabanic acid (cholesterophane), C0[NCH 3 C0] 2, is formed by oxidizing caffeine or by methylating parabanic acid.^ Dimethylparabanic acid (cholesterophane), C0[NCH 3 C0] 2, is formed by oxidizing caffeine or by methylating parabanic acid.

^ Barbituric acid (malonyl urea), CH2[C0 NH]C0.2H20, formed by condensing malonic acid with urea (E. Grimaux, Bull.

^ Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.

.It crystallizes in plates, which melt at 1 45.5° C., and is soluble in cold water.^ It crystallizes in plates, which melt at 1 45.5° C., and is soluble in cold water.

^ It crystallizes in needles which melt at 190° C. (with decomposition), and is readily soluble in hot water.

^ China [CN] Sell Up (urea Phosphate) Up (urea Phosphate) Properties: White Crystal, Easily Soluble In Water, But Not In Organic Solution; Melting Point At 117.3 °c , Its Water Solution Is Strongly Acidic, Ph Value Of 1% Solution...
  • Urea Trade Leads - Urea Manufacturers & Suppliers 10 January 2010 9:24 UTC www.busytrade.com [Source type: FILTERED WITH BAYES]

.Hydrochloric acid at 200° C. decomposes into oxalic acid, carbon dioxide and methylamine, whilst an alcoholic solution of a caustic alkali gives dimethyl urea and oxalic acid.^ Alkaline hypobromites or hypochlorites or nitrous acid decompose urea into carbon dioxide and nitrogen.

^ It is also decomposed by warm aqueous solutions of caustic alkalis, with evolution of ammonia and carbon dioxide.

^ Hydrochloric acid at 200° C. decomposes into oxalic acid, carbon dioxide and methylamine, whilst an alcoholic solution of a caustic alkali gives dimethyl urea and oxalic acid.

.Barbituric acid (malonyl urea), CH2[C0 NH]C0.2H20, formed by condensing malonic acid with urea (E. Grimaux, Bull.^ Barbituric acid (malonyl urea), CH2[C0 NH]C0.2H20, formed by condensing malonic acid with urea (E. Grimaux, Bull.

^ Urea reacts with malonic esters to make barbituric acids.

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

Soc. .Chem.,
1879, 31, 146), crystallizes in prisms, which decompose on heating.^ Acetyl urea, NH 2 CO NH 000H 31 formed by the action of acetic anhydride on urea, crystallizes in needles which melt at 212° C. and, on heating, strongly decomposes into acetamide and cyanuric acid.

^ Chem., 1879, 31, 146), crystallizes in prisms, which decompose on heating.

^ It crystallizes in needles, which melt at 128-130° C., and is decomposed on long heating.

.It yields a nitroso derivative, is nitrated by nitric acid to dilituric acid and brominated by bromine.^ Examples of Phosphate sources include: superphosphate (single, double and/or triple), phosphoric acid, ammonium phosphate, ammonium phosphate sulfate, ammonium phosphate nitrate, diammonium phosphate, ammoniated single superphosphate, ammoniated single superphosphate, ammoniated triple superphosphate, nitric phosphates, potassium pyrophosphates, sodium pyrophosphate, nucleic acid phosphates and phosphonic and phosphorous acid derivatives.
  • Urea phosphite fertilizer - Patent application - new fertilizer comprising Urea Phosphite, which is made by reacting phosphorous acid with urea 10 January 2010 9:24 UTC www.faqs.org [Source type: Reference]

It is a dibasic acid. Veronal (q.v.) is diethyl malonyl urea. For isobarbituric acid see T. B. Johnson and E. V. McCollum, Jour. Biol. Chem., 1906, I, p. .437. Tartronyl urea (dialuric acid), C0[NH CO]CH OH, formed by the reduction of alloxan (J. v.^ Tartronyl urea (dialuric acid), C0[NH CO]CH OH, formed by the reduction of alloxan (J. v.

^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Urea reacts with alcohols to form urethanes and with malonic esters to give barbituric acids .
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

.Liebig and F. Wohler, Ann., 1838, 26, s p.^ Liebig and F. Wohler, Ann., 1838, 26, s p.

.276), or of alloxantin (A. Baeyer, Ann., 1863, 127, p.^ (A. Baeyer, Ann., 1863, 127, p.

.12), crystallizes in needles or prisms and possesses a very acid reaction.^ The process is very simple to carry out; after mixing phosphorous acid with the urea, the reaction system may be heated in view of the endothermic reaction, which takes place.
  • Urea phosphite fertilizer - Patent application - new fertilizer comprising Urea Phosphite, which is made by reacting phosphorous acid with urea 10 January 2010 9:24 UTC www.faqs.org [Source type: Reference]

^ The phosphorous acid to be used as a starting material in the reaction according to the invention may be any urea form commercially available such as crystals, or, diluted liquids.
  • Urea phosphite fertilizer - Patent application - new fertilizer comprising Urea Phosphite, which is made by reacting phosphorous acid with urea 10 January 2010 9:24 UTC www.faqs.org [Source type: Reference]

^ Urea crystallizes in long needles or prisms which melt at 132° C. and sublime when heated in vacuo.

.It becomes red on exposure, and in the moist condition absorbs oxygen from the air, giving alloxantin.^ It becomes red on exposure, and in the moist condition absorbs oxygen from the air , giving alloxantin.

.Allophanic acid, NH 2 C0 NH CO 2 H, is not known in the free state, as when liberated from its salts, it is decomposed into urea and carbon dioxide.^ Urea (NH 2 ) 2 C = O is degraded to carbon dioxide (CO 2 ) and ammonia (NH 3 ) in the rumen by a similar process.
  • G2071 Urea Supplements for Beef Cattle | University of Missouri Extension 10 January 2010 9:24 UTC extension.missouri.edu [Source type: FILTERED WITH BAYES]

^ Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under 3,000 psi pressure and at 350 F. CO2 + 2NH3 > CO(NH2)2 + H2O The removal of water that occurs during the reaction is referred to as "dehydration."
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ Heated mixtures of oxalic acid and urea yielded rapid evolution of gases, carbon dioxide, carbon monoxide and ammonia (if hot, can be explosive).

.Its esters are formed by passing the vapours of cyanic acid into alcohols (W. Traube, Ber., 1889, 22, p.^ Urea reacts with alcohols to form urethanes and with malonic esters to give barbituric acids .
  • urea (chemical compound) -- Britannica Online Encyclopedia 10 January 2010 9:24 UTC www.britannica.com [Source type: Reference]

.1572): [[Conh-Nh 2 Co 2 R-.^ [[Conh-Nh 2 Co 2 R-.

- .Nh2c0 Nh C02r]]; by the action of chlorcarbonic esters on urea (H. Schiff, Ann., 1896, 291, p.^ Nitrourea, H 2 N CO NH NO 2, prepared by adding urea nitrate to wellcooled concentrated sulphuric acid (J. Thiele and A. Lachmann, Ann., 1895, 288, p.

^ Methyl acetyl urea, CH 3 NH CO NH000H 31 is formed by the action of potash on a mixture of bromine (I mol.

^ Urea chloride, NH 2 CO C1 (L. Gattermann, Ann., 1888, 244, p.

.367); and by the action of urethanes on urea chloride (L. Gattermann, Ber., 1888, 21, p.^ Substituted urea chlorides are formed by the direct action of chlorine (F. D. Chattaway and D. F. S. Wunsch, Jour.

^ Those derived from monobasic acids, obtained by the action of acid chlorides or anhydrides on urea, decompose on heating and do not form salts.

^ Urea chlorides are formed by the action of carbonyl chloride on ammonium chloride (at 400° C.), or on salts of primary amines .

293 R). .They are readily decomposed by alkalis, yielding cyanuric acid and ammonia.^ They are readily decomposed by alkalis, yielding cyanuric acid and ammonia.

^ When heated strongly it is decomposed into ammonia and cyanuric acid.

^ Heated mixtures of oxalic acid and urea yielded rapid evolution of gases, carbon dioxide, carbon monoxide and ammonia (if hot, can be explosive).

.Biuret (allophanamide), NH 2 CO NH CO NH 2, is formed by heating urea; by the action of ammonia on allophanic ester; and by heating urea to 140° C. and passing chlorine into the melt at 140-150° C. (J. Thiele, Ann., 1898, 3 0 3, p.^ Biuret is formed during the manufacturing of urea.
  • Urea Fertilizer Carbamide - Russian Producers - Market Trends 10 January 2010 9:24 UTC www.peterpalms.com [Source type: FILTERED WITH BAYES]

^ The waste urea can be recovered in the form of ammonia.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ Biuret (allophanamide), NH 2 CO NH CO NH 2, is formed by heating urea; by the action of ammonia on allophanic ester; and by heating urea to 140° C. and passing chlorine into the melt at 140-150° C. (J. Thiele, Ann., 1898, 3 0 3, p.

95 Anm.). .It crystallizes in needles which melt at 190° C. (with decomposition), and is readily soluble in hot water.^ It crystallizes in thick prisms which melt at 180° C. and is readily soluble in water.

^ It crystallizes in needles and is readily hydrolysed by alkalis.

^ It crystallizes in prisms, which melt at 96° C., and are easily soluble in water.

.When heated strongly it is decomposed into ammonia and cyanuric acid.^ When heated with water it is decomposed into carbon dioxide, ammonia, methylamine and acetic acid .

^ When heated strongly it is decomposed into ammonia and cyanuric acid.

^ They are readily decomposed by alkalis, yielding cyanuric acid and ammonia.

.Baryta water hydrolyses it to carbon dioxide, ammonia and urea.^ Urea is produced commercially from synthetic ammonia and carbon dioxide .
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]
  • Urea - Hwiki 10 January 2010 9:24 UTC hwiki.fzk.de [Source type: Reference]
  • Urea 10 January 2010 9:24 UTC human.freescience.org [Source type: Reference]

^ Baryta water hydrolyses it to carbon dioxide, ammonia and urea.

^ It is hydrolysed by alkalis, giving carbon dioxide, ammonia and sulphuretted hydrogen.

.With silver nitrate and caustic soda it yields a silver salt, Ag2C 2 H 3 N 3 0 2. With nitric acid in the presence of sulphuric acid it yields a nitro derivative.^ With nitric acid in the presence of sulphuric acid it yields a nitro derivative.

^ With silver nitrate and caustic soda it yields a silver salt , Ag2C 2 H 3 N 3 0 2.

^ It yields a nitroso derivative, is nitrated by nitric acid to dilituric acid and brominated by bromine.

Thiourea, or sulphocarbamide, CS(NH 2) 2, is formed by prolonged fusion of ammonium thiocyanate (E. Reynolds, Ann., 1869, 150, p. .224), by passing sulphuretted hydrogen into an ethereal solution of cyanamide (E. Baumann, Ber., 1873, 6, p.^ The pressurized aqueous urea solution passes into heated pipe 3 and into the conversion catalyst 4, contained in an ordinary pipe and positioned inside a heated oven 5.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ (E. Baumann, Ber., 1873, 6, p.

^ Hyponitrous acid is formed by passing nitrous fumes into its methyl alcohol solution.

1 375), or by heating isopersulpho-cyanic acid (F. D. Chattaway, Jour. Chem. .Soc., 1897, 71, p.^ Soc., 1897, 71, p.

612). .It crystallizes in thick prisms which melt at 180° C. and is readily soluble in water.^ It crystallizes in needles which melt at 190° C. (with decomposition), and is readily soluble in hot water.

^ It crystallizes in thick prisms which melt at 180° C. and is readily soluble in water.

^ It crystallizes in prisms, which melt at 96° C., and are easily soluble in water.

.When heated for some time with water to 140° C. in a sealed tube, it is transformed into ammonium thiocyanate, a similar result being obtained by heating the base alone for some hours to 160-170° C. On heating alone for some hours to r70-180° C. it is converted into guanidine thiocyanate.^ When heated for some time with water to 140° C. in a sealed tube, it is transformed into ammonium thiocyanate, a similar result being obtained by heating the base alone for some hours to 160-170° C. On heating alone for some hours to r70-180° C. it is converted into guanidine thiocyanate.

^ It should be noted that similar tests comparing ammonium hydroxide and ammonium carbonate produced identical results under identical test conditions.
  • Method for converting urea to ammonia - Patent 5281403 10 January 2010 9:24 UTC www.freepatentsonline.com [Source type: Reference]

^ From around 170 degrees Celsius the urea is converted into ammonia (NH3) – the actual active agent in this process.
  • Mercedes-Benz launching urea-injected diesel SUVs this fall — Autoblog 10 January 2010 9:24 UTC www.autoblog.com [Source type: General]

.It is hydrolysed by alkalis, giving carbon dioxide, ammonia and sulphuretted hydrogen.^ Baryta water hydrolyses it to carbon dioxide, ammonia and urea.

^ Hydrolysis by alkalis decomposes them into carbon dioxide, amines and ammonia.

^ It is hydrolysed by alkalis, giving carbon dioxide, ammonia and sulphuretted hydrogen.

.It is readily desulphurized by silver oxide, mercuric oxide or lead oxide.^ It is readily desulphurized by silver oxide, mercuric oxide or lead oxide.

.Potassium permanganate oxidizes it to urea (R. Maly, Monats., 1890, II, p.^ Acid potassium permanganate oxidizes it to carbon dioxide and nitrogen.

^ Potassium permanganate oxidizes it to urea (R. Maly, Monats., 1890, II, p.

278). .It acts as a weak base and forms salts with one equivalent of an acid.^ It acts as a weak base and forms salts with one equivalent of an acid.

^ In the forward reaction as shown above glutamate dehydrogenase is important in converting free ammonia and α-KG to glutamate, forming one of the 20 amino acids required for protein synthesis.

^ It behaves as a monobasic acid and forms unstable salts.

.The alkyl derivatives of thiourea are obtained by the action of ammonia and of primary and secondary amines on the mustard oils (A. W. Hofmann, Ber., 1867, I, p.^ The alkyl derivatives of thiourea are obtained by the action of ammonia and of primary and secondary amines on the mustard oils (A. W. Hofmann, Ber., 1867, I, p.

^ Alkyl ureas are formed by the action of primary or secondary amines on isocyanic acid or its esters: [[Conh+Nh2r= R Nhc0nh]] 2 i [[Conr+Nhr 2 =Nr 2 Co Nhr]]; by the action of carbonyl chloride on amines: COC12+2NHR2=C0(NR2)2+2HC1; and in the hydrolysis of many ureides.

^ They can be accessed in the laboratory by reaction of phosgene with primary or secondary amines .

.27): [[Csnr+Nh 3 =Nh 2 Cs Nhr]]; [[Csnr+Nh2r=R Nh Cs Nhr]],.^ [[Csnr+Nh 3 =Nh 2 Cs Nhr]]; [[Csnr+Nh2r=R Nh Cs Nhr]],.

^ CS(NHR) 2 +NH 2 R+HgO--)HgS+RN :C (NHR)2.

or by heating the amide salts of the alkyl dithio-carbaminic acids, viz., .NR CS S(NH 3 R).^ NR CS S(NH 3 R).

.The monoalkyl derivatives are desulphurized by lead hydroxide in the presence of sodium carbonate, the dialkyl and trialkyl derivatives being unaffected (A. E. Dixon, Jour.^ The monoalkyl derivatives are desulphurized by lead hydroxide in the presence of sodium carbonate, the aß dialkyl and trialkyl derivatives being unaffected (A. E. Dixon , Jour.

Chem. .Soc.,
18 93, 6 3, p.^ Soc., 18 93, 6 3, p.

325). .The dialkyl thioureas when digested with mercuric oxide and amines give guanidines.^ The dialkyl thioureas when digested with mercuric oxide and amines give guanidines.

CS(NHR) 2 +NH 2 R+HgO--)HgS+RN :C (NHR)2.
Thiourea and many of its unsymmetrical derivatives have marked physiological action; thiourea causes a slowing of the pulse and respiration, cardiac failure, and death in convulsions; phenyl-, ethyland acetyl-thiourea are actively toxic. The most important derivative pharmacologically is allyl-thiourea, also known as thiosinamine or rhodallin, NH2 CS NH CH2 CH:CH2.
Thiosemicarbazide, NH 2 CS NH NH 2, prepared from hydrazine sulphate, potassium carbonate and thiocyanate (N. Freund, Ber., 1895, 28, p. 94 6; 1896, 29, p. .2501), crystallizes in long needles, which melt at 181-183° C. The addition of sodium nitrite to an aqueous solution of its hydrochloride converts it into amido-triaz / N N sulphol S< 1. The hydrochloride with potassium cyanate C(NH 2): N gives hydrazothio-carbonamide, NH2 C0 NH NH CS NH2. Medicine.-Urea has been given in medicine in doses of 10 to 60 grs.^ The hydrochloride with potassium cyanate C(NH 2): N gives hydrazothio-carbonamide, NH2 C0 NH NH CS NH2.

^ It crystallizes in needles, which melt at 128-130° C., and is decomposed on long heating.

^ C. The addition of sodium nitrite to an aqueous solution of its hydrochloride converts it into amido-triaz / N N sulphol S < 1.

either in mixture or hypodermically. .It has been used with success as an antiperiodic and antipyretic in ague, and also as a diuretic in gout and kidney affections.^ It has been used with success as an antiperiodic and antipyretic in ague , and also as a diuretic in gout and kidney affections.

.Thiosinamine is given internally in doses of to i gr.^ Thiosinamine is given internally in doses of to i gr.

^ Medicine .-Urea has been given in medicine in doses of 10 to 60 grs.

in capsule. .Larger doses usually upset the digestion.^ Larger doses usually upset the digestion.

.It has been used for the cure of lupus and of keloid, in which case it is administered hypodermically.^ It has been used for the cure of lupus and of keloid, in which case it is administered hypodermically.

.In keloid 20 minims of a t o % solution is injected directly into the part.^ He has also had success treating malignant pleural effusions, by injecting a 10-percent sterile solution of urea directly into the pleural cavity.
  • Urea for Cancer, ALTERNATIVES IN CANCER THERAPY by Ross, R.Ph. Pelton, Lee Overholser 10 January 2010 9:24 UTC www.curezone.com [Source type: Academic]

^ The urea crystals may be directly packed into the wound or a strong or saturated solution may be applied.

^ In localized, advanced tumors of the breast, he reports excellent results from injecting a 50-percent urea solution into the mass of the tumor every two to four days.
  • Urea for Cancer, ALTERNATIVES IN CANCER THERAPY by Ross, R.Ph. Pelton, Lee Overholser 10 January 2010 9:24 UTC www.curezone.com [Source type: Academic]

It causes a local reaction with absorption of the scar tissue. .For this reason it is used to remove corneal opacities, deafness due to thickening of the membrane, stricture of the oesophagus and hypertrophy of the pylorus, it has also been successful in the treatment of adhesive parametritis.^ In closing, Dr. Danopoulos states that perhaps the greatest value of urea in the treatment of malignancies is its prophylactic use after removal of the primary tumor.
  • Urea for Cancer, ALTERNATIVES IN CANCER THERAPY by Ross, R.Ph. Pelton, Lee Overholser 10 January 2010 9:24 UTC www.curezone.com [Source type: Academic]

.Fibrolysin is a modified form of thiosinamine made by mixing it with sodium salicylate Fibrolysin is freely soluble and may be given in hypodermic or intra-muscular injection.^ Due to extensive hydrogen bonding with water (up to six hydrogen bonds may form, two from oxygen atom and one from each hydrogen), it is very soluble and thus is also a good fertiliser.

^ Due to extensive hydrogen bonding with water (up to six hydrogen bonds may form, two from the oxygen atom and one from each hydrogen), it is very soluble and thus is also a good fertilizer.
  • What is Urea? 10 January 2010 9:24 UTC ipedia.net [Source type: Reference]

Like thiosinamine it has a specific action on scar tissue and has been used in urethral strictures. .Both these preparations should only be used in cases where it is possible to exclude any tuberculous foci, or by their action in breaking down protective fibrous tissues they may cause a quiescent lesion to become active.^ Keeping crop protection chemicals on the crop for which they are intended has been a cornerstone of farming not only to protect neighboring crops, but to not waste money allowing products to drift off the intended target.
  • Nitrogen fertilizer situation and outlook 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]
  • Agrotain: boosting urea efficiency 10 January 2010 9:24 UTC deltafarmpress.com [Source type: General]

^ (These are not abbreviations of the sort that one should use in writing, incidentally.
  • SBF Glossary: UR to .uy 10 January 2010 9:24 UTC www.plexoft.com [Source type: FILTERED WITH BAYES]

^ These fertilizers and fungicides are marketed either as solids or liquids; the fertilizers and/or fungicides are dissolved in spray tanks for foliar applications, or are used to prepare concentrated stock solutions for ground application.
  • Urea phosphite fertilizer - Patent application - new fertilizer comprising Urea Phosphite, which is made by reacting phosphorous acid with urea 10 January 2010 9:24 UTC www.faqs.org [Source type: Reference]

.In large doses toxic symptoms are produced, death following on coma.^ Symptoms of UCDs usually arise at birth and encompass, ataxia, convulsions, lethargy, poor feeding and eventually coma and death if not recognized and treated properly.

^ Tolerable and toxic doses of urea : It is difficult to define a toxic level of dietary urea for ruminants, as their ability to metabolise large amounts of dietary urea safely depends on many factors.
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]

^ Tolerable and toxic doses of nitrite and nitrate : These are difficult to define, as there is wide variation in the amount of met-Hb produced by the same dose of NO 3 - .
  • Urea, nitrate & nitrite poisoning in cattle & sheep: Sources, toxic doses, treatment and prevention 10 January 2010 9:24 UTC homepage.eircom.net [Source type: FILTERED WITH BAYES]



Simple English

Urea
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Infobox disclaimer and references

Urea is an organic compound. It was first found in urine in 1773 by the French chemist Jean Rouelle. It is also called Carbamide, and its chemical names are Carbonyl Diamide (used in inorganic chemistry) and Diaminomethanal (used in organic chemistry).

In humans, it is a normal component of blood and many body tissues. It is produced in the liver, where ammonia, a highly toxic substance, is converted into urea, which has a very low toxicity (it is several times less toxic than common salt). Most of the urea produced in this way is not needed by the body, and is removed from the blood iin the kidneys and released as a waste product in urine.

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