In chemical kinetics a<unk>  k or 
λ
{\displaystyle \lambda }
 quantifies the speed of a chemical<unk> .
For a chemical<unk>  where substance A and B are<unk> g to produce C, the<unk> <unk>  has the form:
k(T) is the<unk>  that depends on temperature.
[X] is the concentration of substance X in moles per volume of solution assuming the<unk>  is taking place throughout the volume of the solution. (for a<unk>  taking place at a boundary it would denote something like moles of X per area.)
The exponents m and n are called orders and depend on the<unk>  mechanism. They can be determined experimentally.
In a  single-step<unk>  can also be written as
Ea is the activation energy and R is the Gas<unk> .  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 Arrhenius equation gives the quantitative basis of the relationship between the activation energy and the<unk> <unk>  at which a<unk>  proceeds.
The units of the<unk>  coefficient depend on the global order of<unk> :
For order zero, the<unk>  coefficient has units of mol L-1 s-1 or mol dm-3 s-1
For order one, the<unk>  coefficient has units of s-1
For order two, the<unk>  coefficient has units of L mol-1   s-1 or mol-1 dm3 s-1
For order n, the<unk>  coefficient has units of mol1-n Ln-1 s-1 or mol1-n dm3n-3 s-1
Reaction rate constant
Quantum yield
Gas constant
Greenhouse effect
Equation of state
Spin quantum number
Extraction ratio
Gibbs free energy