Q. Assertion: In rate law, unlike in the expression for equilibrium constants, the exponents for concentrations do not necessarily match the stoichiometric coefficients.
Reason: It is the mechanism and not the balanced chemical equation for the overall change that governs the reaction rate.

 3102  171 AIIMSAIIMS 2009Chemical Kinetics Report Error

Solution:

Rate law is always written according to the slowest step and thus exponents for concentrations do not necessarily match the stoichiometric coefficients