Question

One-Step Mechanism: NO2 (g) + CO(g) --> NO(g) + CO2 (g)

Two-Step Mechanism: Step 1 NO2 (g) + NO2 (g) --> NO(g) + NO3(g)
Step 2 NO3(g) + CO(g) ⇌ NO2 (g) + CO2 (g). What is the rate law for the one-step mechanism?

Answer 1

The rate law for the one-step mechanism involving NO₂ and CO is rate = k₁[NO₂]², reflecting the rate-determining step of the reaction.

Step-by-step explanation:

The rate law for the one-step mechanism of the reaction between nitrogen dioxide (NO₂) and carbon monoxide (CO) producing nitrogen oxide (NO) and carbon dioxide (CO₂) is derived from the rate of the slowest step in the reaction mechanism. Since the experimentally determined rate law for the reaction matches that of the first step, we conclude that the first step is the rate-determining step. Hence, the overall rate law for the reaction will reflect this slow step.

The rate law for the reaction is then given by rate = k₁[NO₂]², where k₁ is the rate constant for the rate-determining step and [NO₂] represents the concentration of nitrogen dioxide.