Question

Consider the reaction:
\( \text{Cl}_2 (aq) + \text{H}_2\text{S} (aq) \rightarrow \text{S} (s) + 2\text{H}^+ (aq) + 2\text{Cl}^- (aq) \)
The rate equation is \( \text{rate} = k[\text{Cl}_2][\text{H}_2\text{S}] \).
Which of the following mechanisms is/are consistent with this rate equation?

• A. Only A
• B. Only B
• C. Both A and B
• D. Neither A nor B

Hint:

Rate law reflects molecularity of the rate-determining step.

Answer 1

The Correct Option is A

Step 1: Rate law depends on reactants in slow step.
Step 2: Mechanism A has slow step involving Cl₂ and H₂S directly.
Step 3: Mechanism B involves HS⁻ in slow step, which contradicts given rate law.