Given…Overall reaction:
2 NO2 (g) + F2 (g) → 2 NO2F (g)
Rate = k[NO2][F2]
a. Can this be a single step reaction?
b. Postulate a mechanism using experimental data and chemical intuition come up with a mechanism that fits.
a. Can this be a single step reaction?
To determine if a reaction can be a single-step reaction, we need to check if the stoichiometry of the reaction matches the rate equation. In this case, the stoichiometry shows that 2 moles of NO2 react with 1 mole of F2 to produce 2 moles of NO2F. The rate equation given is Rate = k[NO2][F2].
Since the coefficients in the balanced equation match the exponents in the rate equation, it suggests that this reaction can indeed be a single-step reaction. This means that the overall reaction occurs in a single elementary step.
b. Postulate a mechanism using experimental data and chemical intuition to come up with a mechanism that fits.
To propose a mechanism for this reaction, we need to consider the experimental data and chemical intuition. One possible mechanism for the given reaction is as follows:
Step 1: NO2 (g) + F2 (g) → NO2F (g) + F (g) (forward reaction)
Step 2: F (g) + NO2 (g) → NO2F (g) (reverse reaction)
This mechanism involves two elementary steps. In the first step, NO2 and F2 react to form NO2F and a free fluorine radical, F. In the second step, the free fluorine radical, F, reacts with NO2 to reform NO2F.
The rate-determining step (the slowest step) in this mechanism is likely to be Step 1 because it involves the breaking of the F-F bond.
Overall, this proposed mechanism is consistent with the given rate equation, as the rate-determining step involves the reactants NO2 and F2. However, it's important to note that the proposed mechanism is postulated based on experimental data and chemical intuition, and further experimental evidence would be needed to verify its accuracy.