Question

1)Thallium (I) is oxidized by cerium (IV) as follows: Tl+ + 2 Ce+4  Tl+3 + 2 Ce+3

The elementary steps, in the presence of Mn(II), are as follows:
Step 1 Ce+4 + Mn+2 --- Ce+3 + Mn+
Step 2 Ce+4 + Mn+3 ---- Ce+3 + Mn+4 Step 3 Tl+ + Mn+4 ----- Tl+3 + Mn+2
(a) Identify the catalyst, intermediates, and the rate determining step if the rate law is r = k[Ce+4[Mn+2].
(b) Explain why the reaction is slow without a catalyst.

Answer 1

Iron (III)

Answer 2

(a)catalyst Mn2+
intermediates Mn3+,Mn+, Mn4+
RDS Step 2
(b)require high activation energy for reaction to occur