k(T) is the reaction rate constant that depends on temperature.
[C] is the concentration of substance C in moles per volume of solution assuming the reaction is taking place throughout the volume of the solution (for a reaction taking place at a boundary it would denote something like moles of C per area).
A single-step reaction can also be written as
Ea is the activation energy and R is the Gas constant. Since at temperature T the molecules have energies according to a Boltzmann distribution, one can expect the proportion of collisions with energy greater than Ea to vary with e-Ea/RT. A is the pre-exponential factor or frequency factor.
The units of the rate coefficient depend on the global order of reaction:
Calculation of rate constants of the processes of generation and relaxation of electronically and vibrationally excited particles are of great importance. It is used in the computer simulation of processes in plasma chemistry, microelectronics. First-principle based models should be used for such calculation. It can be done with the help of computer simulation software.