Question

Group-13 elements react with O₂ in amorphous form to form oxides of type M₂O₃ (M = element). Which among the following is the most basic oxide?

• A. Al₂O₃
• B. Tl₂O₃
• C. Ga₂O₃
• D. B₂O₃

Answer 1

The Correct Option is B

Group 13 Oxide Basicity 

As we move down Group 13, the metallic character increases, and hence the electropositive character increases. As electropositivity increases, the basicity of the oxides increases.

The order of basicity for Group 13 oxides is \( \text{B}_2\text{O}_3 < \text{Al}_2\text{O}_3 < \text{Ga}_2\text{O}_3 < \text{In}_2\text{O}_3 < \text{Tl}_2\text{O}_3 \).

Conclusion:

\( \text{Tl}_2\text{O}_3 \) is the most basic oxide.