Question

Relative stability orders of +1, +3 oxidation states of Ga, In, Tl are respectively

• A. $ \text{Tl}^+>\text{In}^+>\text{Ga}^+ $, $ \text{Ga}^{3+}>\text{In}^{3+}>\text{Tl}^{3+} $
• B. $ \text{Ga}^+>\text{In}^+>\text{Tl}^+ $, $ \text{Tl}^{3+}>\text{In}^{3+}>\text{Ga}^{3+} $
• C. $ \text{Ga}^+>\text{In}^+>\text{Tl}^+ $, $ \text{Ga}^{3+}>\text{In}^{3+}>\text{Tl}^{3+} $
• D. $ \text{Tl}^+>\text{In}^+>\text{Ga}^+ $, $ \text{Tl}^{3+}>\text{In}^{3+}>\text{Ga}^{3+} $

Hint:

The inert pair effect is key to understanding the stability of oxidation states in heavier p-block elements.

Answer 1

The Correct Option is A

 To understand the relative stabilities of the +1 and +3 oxidation states for Ga (gallium), In (indium), and Tl (thallium), we need to consider the inert pair effect and general periodic trends.

Explanation:

The oxidation states being analyzed are +1 and +3. For elements like Ga, In, and Tl, which belong to the same group, the stability of these oxidation states is influenced by the so-called inert pair effect, which is more pronounced in heavier elements.

Relative Stability of +1 Oxidation State:

• Tl⁺ > In⁺ > Ga⁺: In heavier elements like Tl, the +1 oxidation state is relatively more stable due to the inert pair effect, where the s-electrons are less available for bonding and remain non-bonded. This effect becomes more pronounced as you move down the group from Ga to Tl.

Relative Stability of +3 Oxidation State:

• Ga³⁺ > In³⁺ > Tl³⁺: The +3 oxidation state is most stable at the top of the group (Ga) and decreases in stability as you move down the group to Tl.

Conclusion: This analysis agrees with the given correct answer, emphasizing the stability trends for the +1 and +3 states:

$ \text{Tl}^+ > \text{In}^+ > \text{Ga}^+ $, $ \text{Ga}^{3+} > \text{In}^{3+} > \text{Tl}^{3+} $