Question

What is the overall reaction order for the following rate law: rate = k [A]2[B]?

Answer 1

Since each of the two reactants is first order, the overall reaction order is second.

Answer 2

The overall reaction order for the rate law rate=k[A]^2[B] is 3. The order is the sum of the molecularity of the reactants. In this case, A has a molecularity of 2 and B has a molecularity of 1. The sum is the overall order of the reaction which is 2+1, equal to 3.