🤓 Based on our data, we think this question is relevant for Professor Costanza's class at USF.
Consider the reaction
Cl2 (aq) + H2S (aq) → S (s) + 2 H+ (aq) + 2 Cl - (aq)
The rate equation for this reaction is
rate = k [Cl2] [H2S]
Which of these mechanisms is (or are) consistent with this rate equation?
I Cl2 + H2S → H+ + Cl - + Cl+ + HS - (slow)
Cl+ + HS - → H+ + Cl - + S (fast)
II H2S ⇌ H+ + HS - (fast equilibrium)
Cl2 + HS - → 2Cl - + H+ S (slow)
(A) I only
(B) II only
(C) Both I and II
(D) Neither I or II
We’re being asked to determine the reaction mechanism that is consistent with the given rate law for this reaction:
Cl2(aq) + H2S(aq) → S(s) + 2 H+(aq) + 2 Cl–(aq)
Recall that a reaction mechanism is a sequence of single steps that add up to the chemical reaction. The rate law of the reaction depends on the rate-determining step of the mechanism, which is the slow step in the mechanism.