Question

Consider the reaction :
Cl_2(aq) + H₂S_(aq) → S_(s) + 2H⁺_(aq) + 2Cl^–_(aq)
The rate of reaction for this reaction is rate = k[Cl₂][H₂S]
Which of these mechanism is/are consistent with this rate equation ?
A. Cl₂ + H₂S → H⁺ + Cl^– + Cl⁺ + HS^– (slow)
Cl⁺ + HS^–→ H⁺ + Cl^– + S (fast)
B. H₂S ⇔ H⁺ + HS^– (fast equilibrium)
Cl₂ + HS^– → 2Cl^– + H⁺ + S (slow)

(a) A only 

(b) B only

(c) Both A and B 

(d) Neither A nor B

Answer 1

(a) :- The rate equation depends upon the rate determining step. The given rate equation is only consistent with the mechanism A.