Chemistry

Problem

For the reaction

C + D \to \text{products}

the observed rate law is

\text{rate} = k\,[C]^2

. Three mechanisms are proposed. I. Step 1 (slow):

C + C \to \text{intermediate} \to \text{products}

II. Step 1 (slow):

C + D \to \text{intermediate}

Step 2 (fast):

\text{intermediate} + C \to \text{products}

IV. Single elementary step:

2\,C \to \text{products}

(slow) Based on the rate law, which mechanism is impossible? a) Mechanism I b) Mechanism IV c) Mechanism II