Final answer:
The overall balanced chemical equation is 2NO(g) + O2(g) → 2NO2(g), with N2O4(g) as the intermediate. The rate-determining step of the mechanism is the first step, consistent with the experimentally determined rate law which is rate = k[NO]^2[O2].
Step-by-step explanation:
The question involves reaction mechanisms and the determination of rate laws in chemistry. To address the parts of the question:
(a) Overall Balanced Chemical Equation
The overall balanced chemical equation for the reaction is derived by adding the elementary steps and cancelling any intermediates to get 2NO(g) + O2(g) → 2NO2(g).
(b) Intermediate in the Reaction Mechanism
The intermediate in the proposed reaction mechanism is N2O4(g), as it is produced in the first step and consumed in the second step and does not appear in the overall balanced equation.
(c) Rate-Determining Step
Given the experimentally determined rate law equation rate = k[NO]^2[O2], this suggests that the first step is the rate-determining step. This is because the rate law directly corresponds to the concentrations of reactants in the first step, indicating that the formation of N2O4(g) is the slowest and therefore the rate-limiting step.