Chapter 12, Problem 76E

The reaction of CO with CI₂ gives phosgene (COCI₂), a nerve gas that was used in World War I. Use the mechanism shown here to complete the following exercises:

${\text{CI}}_2\left(g\right)\rightleftharpoons 2\text{CI}\left(g\right)$ (fast, k₁ represents the forward rate constant, k_-1 the reverse rate constant)

$\text{CO}\left(g\right)+\text{CI}\left(g\right)\to \text{COCI}\left(g\right)$ (slow, k₂ the rate constant)

$\text{COCI}\left(g\right)+\text{CI}\left(g\right)\to {\text{COCI}}_2\left(g\right)$ (fast, k₃ the rate constant)

(a) Write the overall reaction.

(b) Identify all intermediates.

(c) Write the rate law for each elementary reaction.

(d) Write the overall rate law expression.