Final answer:
The reaction order with respect to N₂ in the rate law rate = k[N₂][H₂]² is 1, making it first-order in N₂. The order with respect to H₂ is 2, making it second-order in H₂. Consequently, the overall reaction order is third-order.
Step-by-step explanation:
Understanding the Reaction Order
The reaction order in the rate law rate = k[N₂][H₂]² with respect to N₂ is 1 as the concentration of N₂ is raised to the power of 1 in the rate equation. In chemistry, the exponent to which the concentration of a reactant is raised in the rate equation indicates the order of the reaction with respect to that reactant. Since the concentration of N₂ appears to the first power, the reaction is first-order in N₂.
The reaction order in H₂ is 2, as indicated by the square of the [H₂] concentration term in the rate law. Thereby, the overall order of the reaction is calculated by adding the exponents of each reactant concentration (1 for N₂ and 2 for H₂), giving us a total of 3. This makes the reaction third-order overall.