(a). Explain why `Mn^(3+)` is less stable than `Mn^(22+)` and `M^(4+)` ions? (b). Standard reduction potential of copper is greatr than that of hydrogen yet is librates hydrogen from a concentrated solution of hydrochloric acid. Explain this fact with proper reasoning. `Cu^(2+)+2etoCu_(s)` `E_((Cu^(2+))/(Cu))^(ɵ)=0.34"volt"` `2H^(o+)+2etoH_(2(g))` `E_((H^(o+))/(H_2))=0.00"volt"` (c). An aqueous solution of `FeCl_3` is slightly yellowish in colour. (d). `Cu(I)` compounds are not known in aqueous solution.

(a). Explain why `Mn^(3+)` is less stable than `Mn^(22+)` and `M^(4+)`

1.	(a). Explain why `Mn^(3+)` is less stable than `Mn^(22+)` and `M^(4+)` ions? (b). Standard reduction potential of copper is greatr than that of hydrogen yet is librates hydrogen from a concentrated solution of hydrochloric acid. Explain this fact with proper reasoning. `Cu^(2+)+2etoCu_(s)` `E_((Cu^(2+))/(Cu))^(ɵ)=0.34"volt"` `2H^(o+)+2etoH_(2(g))` `E_((H^(o+))/(H_2))=0.00"volt"` (c). An aqueous solution of `FeCl_3` is slightly yellowish in colour. (d). `Cu(I)` compounds are not known in aqueous solution.
Answer» (a). `Mnto3d^5,4s^2`, `Mn^(3+)to3d^4,4s^(0)` `Mn^(2+)to3d^5,4s^0`,`Mn^(4+)to3d^3,4s^0` On the basis of electron configuration `Mn^(2+)` and `Mn^(4+)` are expected to be more stable, hence `Mn^(3+)` undregoes disproportionation. `2Mn^(3+)toMn^(2+)+(mn^(4+)` (b). When copper is treated with conc.HCl then formation of stable complex ion `[CuCl_4]^(2-)` along with liberation of `H_2` gas takes place. `Cu+4HCl_((conc.))to[CuCl_4]^(2-)+2H^(o+)+H_2uarr]` (c). An equeous solution of `FeCl_3` is colloidal. It is yellowish in colour due to Tyndall Effect. (d). `Cu(I)` compounds undergo disproportionation in aqueous medium. `Cu_2Cl_2toCuCl_2+Cu`