Question

The stability of + 1 oxidation state among Al, Ga, In and Tl increases in the sequence

(a) Al < Ga < In < Tl 

(b) Tl < In < Ga < Al

(c) In < Tl < Ga < Al 

(d) Ga < In < Al < Tl

Answer 1

The correct option is: (a) Al < Ga < In < Tl 

Explanation:

In group 13 elements, stability of +3 oxidation state decreases down the group while that of +1 oxidation state increases due to inert pair effect. 

Hence, stability of +1 oxidation state increases in the sequence : Al < Ga < In < Tl