Arange the following in correct order of stability.
(i) `Ga' In, TI'` (ii) `As^(+5),Sb^(+5), B^(+5)`

Answer

`Ga^(+) lt In^(+) lt TI^(+)` (ii) `As^(+5) gt Sb^(+5) gt Bi^(5+)`

Explanation

(i) In group-13, stability of `+1` oxidation state increases on moving down the group, due to inert pair effect
(ii) In group-15, stability of `+5` oxidation state decreases on moving down the group, due to inert pair effect