The reaction : has the following mechanism

CHEMISTRY · Single correct · AP · Chemistry · Kinetics · Kinetics

Problem

The reaction :

\text{CO} + \text{Cl}_2 \longrightarrow \text{COCl}_2

has the following mechanism. (i)

\text{Cl}_2 \xrightleftharpoons{K_1}{K_2} 2\text{Cl}

(fast) (ii)

\text{Cl} + \text{CO} \xrightleftharpoons{K_1}{K_2} \text{COCl}

(fast) (iii)

\text{COCl} + \text{Cl}_2 \xrightarrow{K_3} \text{COCl}_2 + \text{Cl}

(slow) The rate expression will be : (1)

r = K[\text{CO}][\text{Cl}_2]

(2)

r = K[\text{CO}][\text{Cl}_2]^{3/2}

(3)

r = K[\text{CO}]^2[\text{Cl}_2]

(4)

r = [\text{CO}]^{3/2} [\text{Cl}_2]