Explain why `Zn^(2+)` salts are colouless while `Ni^(2+)` salts are coloured ?

Explain why Zn^(2+) salts are colourless while Ni^(2+) salts are coloured ?

Why Zn^(2+) salts are white while Ni^(2+) salts are blue

(a) What is Lanthanoid contration ? What are its important effects ? (b) Account for the following : (i) Zn^(2+) salts are white while Ni^(2+) salts are coloured. (ii) Ionisation enthalpies of 5d series elements are higher than the corresponding 3d series elements

Zn^(2+) salt are white while Cu^(2+) salts are blue. Assign reason.

Ions of Zn^(2+) and Ti^(4+) are colourless while Cu^(2+) and Ni^(2+) are coloured. Why?

(a) Why are Zn^(2+) salts white while Cu^(2+) salts are blue ? (b) What is meant by 'disproportionation' ? Write the disproportionation reaction of Cu^+ in aqueous solution.