Consider the reaction and the rate law below.
2o3 -> 3o2
r=k[o3]^2
what is the overall order of the reactants in this rate law?
0
1
2
3

Explanation:

The reaction and rate law are:

The order of the reaction respect any reactant is the exponent to which the concentration of the reactant appears raised to in the rate law expression, and the overall order of the reactants is the sum of the orders for each reactant.

So, in the rate law r = k [O₃]² the order respect to the reactant O₃ is 2, and, since it is the only reactant that appears in the rate law, the overall order is also 2.