Question

The reaction and rate law for the gas-phase decomposition of dinitrogen pentaoxide are 2 N₂O₅(g) → 4 NO₂(g) + O₂(g) Rate = k [N₂O₅]which of the following can be considered valid mechanisms for the reaction?

A)one-step collision
B) 2 N₂O₅(g) → 4 NO₃(g) + 2 NO₂(g) → 4 NO₂(g) + 2 O₂(g)
C) N₂O₅(g) ⇌ NO₃(g) + NO₂(g)
N₂O₅(g) → 3 NO₂(g) + O(g)
NO₃(g) + O(g) → NO₂(g) + O₂(g)
D) 2 N₂O₅(g) ⇌ 2 NO₂(g) + N₂O₃(g)
N₂O₃(g) + 3 O(g) → 2 NO₂(g) + 2 O(g) → O₂(g)
E) 2 N₂O₅(g) → N₄O₁₀(g)
N₄O₁₀(g) → 4 NO₂(g) + O₂(g)

F)none of the above

Answer 1

Option B is a valid mechanism for the decomposition of dinitrogen pentoxide as it includes a rate-determining step that aligns with the given rate law and accounts for the correct stoichiometry of the products.

Step-by-step explanation:

The question asks which of the provided mechanisms can be considered valid for the gas-phase decomposition of dinitrogen pentoxide, given the rate law Rate = k [N₂O₅]. Option B (2 N₂O₅(g) → 4 NO₃(g) + 2 NO₂(g) → 4 NO₂(g) + 2 O₂(g)) suggests a mechanism with two steps. The first step yields NO₃ and NO₂, which is consistent with the formation of NO₂ in the overall reaction. The second step involves the conversion of NO₃ to NO₂ and O₂, consistently accounting for the observed stoichiometry and the rate law which depends solely on the concentration of N₂O₅. This suggests that the first step of the mechanism is the rate-determining step, aligning with the given rate law.