Rate Law vs. Rate of reaction
Posted: Wed Mar 07, 2018 1:52 am
I'm a bit confused on the difference between the rate of reaction, which is the change in the concentration of a species over change in time and rate law?
Rate law seems to be the same idea so i'm a bit confused.
Re: Rate Law vs. Rate of reaction [ENDORSED]
Posted: Wed Mar 07, 2018 7:54 am
The rate law and the rate of reaction are different. The rate of reaction (in terms of disappearance of reactant A) is -d[A]/dt.
The rate law relates the rate to an expression involving the rate constant k and the initial concentrations of reactants. The rate law for A + 2B --> C is:
rate = k[A][B]^2
assuming that A + 2B --> C is an elementary reaction. If it is not, the exponents will need to be determined experimentally.
The rate is usually the unique rate.