Final answer:
The rate equation shows that the reaction is second-order with respect to NO and first-order with respect to H₂, making the overall reaction third-order in sum.
Step-by-step explanation:
The question deals with chemical kinetics and the determination of reaction orders from a rate equation. The provided rate equation rate = k[NO]²[H₂] indicates that the reaction is second-order with respect to nitric oxide (NO) because the concentration of NO is squared, and it is first-order with respect to hydrogen (H₂) as the concentration of hydrogen appears to the first power in the rate equation.
Thus, for the reaction H₂(g) + 2NO(g) → N₂O(g) + H₂O(g), the order with respect to NO is 2, and the order with respect to H₂ is 1. The overall order of the reaction is the sum of the orders with respect to each reactant, which in this case is 2 + 1 = 3, making the reaction third-order overall. This is a key concept in chemical kinetics, which is the study of how chemical reactions proceed and how their rates can be described and manipulated.