(a) (i) Account for the following:
(1) `Zn^(2+)` salts are colourless while `Ni^(2+)`salts are coloured.
(2) `Cr^(2+)` is a strong reducing agent.
(3) Transition metals and their compounds show catalytic activities.

(ii) Write the ionic equations for the oxidizing action of `MnO_4^-` in acidic medium with
(1) `I^-` ion , and
(2) `Fe^(2+)` ion