Question

Choose the correct stability order of group 13 elements in their +1 oxidation state

• A. Al < Ga < In < Tl
• B. Tl < In < Ga < Al
• C. Al < Ga < Tl < In
• D. Al < Tl < Ga < In

Answer 1

The Correct Option is A

The question requires us to determine the correct order of stability of Group 13 elements in their +1 oxidation state. Let's analyze the options using the concept of inert pair effect and the general trend observed in the periodic table.

Group 13 elements include Boron (B), Aluminum (Al), Gallium (Ga), Indium (In), and Thallium (Tl). As we move down the group, the stability of the +1 oxidation state increases. This is due to the inert pair effect, where the s-electrons (in the outermost shell) are less likely to participate in bonding as we move to heavier elements.

The inert pair effect causes the heavier elements (like Tl) to prefer lower oxidation states. Consequently, in Group 13, the stability of the elements in the +1 oxidation state increases from Al to Tl.

1. Al (Aluminum): Shows the least stability in the +1 oxidation state due to the absence of significant inert pair effect.
2. Ga (Gallium): Has slightly increased stability compared to Al, due to the beginning of the inert pair effect.
3. In (Indium): Shows even higher stability as the effect is more pronounced.
4. Tl (Thallium): Exhibits the highest stability in the +1 oxidation state because the inert pair effect is strongest, making it reluctant to exhibit the +3 state.

From the analysis above, the correct order of stability for these elements in their +1 oxidation state is:

Al < Ga < In < Tl

Therefore, the correct option is:

Option 1: Al < Ga < In < Tl

In conclusion, the stability of the +1 oxidation state increases down the group from Al to Tl due to the increasing impact of the inert pair effect on heavier elements.