Question

for the reaction mechanism shown, identify the intermediate(s).

cl2(g) ⇌ 2cl(g)

chcl3(g) + cl(g) ⇌ hcl(g) + ccl3(g)

ccl3(g) + cl(g) ⇌ ccl4(g)

Explanation:

Step1: Recall intermediate definition

An intermediate is a species that is produced in an early - step of a reaction mechanism and consumed in a later step.

Step2: Analyze each step

In the first step, $\mathrm{Cl}_2(\mathrm{g})
ightleftharpoons2\mathrm{Cl}(\mathrm{g})$, $\mathrm{Cl}(\mathrm{g})$ is produced. In the second step $\mathrm{CHCl}_3(\mathrm{g})+\mathrm{Cl}(\mathrm{g})
ightleftharpoons\mathrm{HCl}(\mathrm{g})+\mathrm{CCl}_3(\mathrm{g})$, $\mathrm{Cl}(\mathrm{g})$ is consumed and $\mathrm{CCl}_3(\mathrm{g})$ is produced. In the third step $\mathrm{CCl}_3(\mathrm{g})+\mathrm{Cl}(\mathrm{g})
ightleftharpoons\mathrm{CCl}_4(\mathrm{g})$, $\mathrm{CCl}_3(\mathrm{g})$ is consumed.

Answer:

$\mathrm{Cl}(\mathrm{g})$ and $\mathrm{CCl}_3(\mathrm{g})$