Question

A chemical reaction occurs in two steps:

1. \[\ce{NO2Cl_{(g)} ->[slow] NO2_{(g)} + Cl_{(g)}}\]
2. \[\ce{NO2Cl_{(g)} + Cl_{(g)} ->[fast] NO2_{(g)} + Cl2_{(g)}}\]

1. Write down the rate law.
2. Identify the reaction intermediate.

Answer 1

a. Since the first step is slow (rate-determining step), the rate depends on the reactant involved in that step.

Rate = k[NO₂Cl]

b. An intermediate is formed in one step and consumed in another.

Here, Cl (chlorine atom) is produced in step (i) and consumed in step (ii).

Cl is the reaction intermediate.