Question

The following is a proposed mechanism for the reaction NO₂ (g) + CO (g) --> NO (g) + CO₂ (g). The rate law for the reaction is rate = k [NO₂]² a) is this a plausible mechanism? Explain. B) identify the reactants, intermediates, and products. NO₂ (g) + NO₂ (g)--> NO₃ (g) + NO (g) (slow) and NO₃ (g) + CO (g) --> NO₂ (g) + CO₂ (g) (fast)

Answer 1

Solution

a)

The rate law for the reaction is rate = k[NO₂]²

From this reaction it is clear that rate of this reaction depends only upon the concentration of NO₂. In the given mechanism, the rate of condensation of two molecules of NO₂ is slower than the decomposition of formed intermediate. Also we know that rate of reaction depends uopon the slowest step. Therefore, the given mechanism is plaussible mechanism for the given reaction.

b)

In the given mechanism. NO₂ and CO are the reactants and NO and CO₂ are the products. NO₃ formed in the reaction is intermediate. This is because it is produced from reactants and used in the production of products. The NO₂ formed in the reaction behaves as both, intermediate and reactants.