The manganese(II)-catalyzed redox reaction between cerium(IV) and thallium(I) is thought to proceed by a three-step mechanism: Ce4+(aq) + Mn2+(aq) --> Ce3+(aq) + Mn3+(aq) (slow)
Ce4+(aq) + Mn3+(aq) --> Ce3+(aq) + Mn4+(aq)
Mn4+(aq) + Tl+(aq) --> Mn2+(aq) + Tl3+(aq)

a. If the first step of this mechanism is rate-determining (slow), choose the correct rate law for the overall process.

1. Rate = k [Ce4+]2
2. Rate = k [Ce4+] [Tl+]
3. Rate = k [Mn2+] [Mn3+]
4. Rate = k [Mn2+] [Ce4+]
5. Rate = k [Mn3+] [Tl+]
6. Rate = k [Ce4+]2 [Tl+]

b. Choose the correct chemical equation for the overall process.

1. Ce4+(aq) + Mn2+(aq) --> Ce3+(aq) + Mn3+(aq)
2. Ce4+(aq) + Mn3+(aq) --> Ce3+(aq) + Mn4+(aq)
3. 2Ce4+(aq) + Tl+(aq) --> 2 Ce3+(aq) + Tl3+(aq)