The stability of +1 oxidation state among Al, Ga, In and Tl increases in the sequence
- Al < Ga < In < Tl
- Tl < In < Ga < Al
- In < Tl < Ga < Al
- Ga < In < Al < Tl
Answer
(1) Al < Ga < In < Tl
Solution
As per NCERT, on moving down group 13 the inert pair effect increases: the ns2 electrons take less part in bonding.
the stability of the +1 oxidation state increases down the group (Tl+ is more stable than Tl3+).
Order of stability of +1 state: Al < Ga < In < Tl
Answer: (1)