Question

Which of the following is the most basic oxide?

• A. $S{b}_2{O}_3$
• B. $B{i}_2{O}_3$
• C. $Se{O}_2$
• D. $A{l}_2{O}_3$

Answer 1

Answer: (B)

$B{i}_2{O}_3$ is the most basic oxide.
More the oxidation state of the central metal atom, more is its acidity. Hence , $Se{O}_2$ ($O.S$ of $Se=+4$) is acidic. Further, for a given oxidation state, the basic character of the oxides increases with increasing size of the central atom. Thus, $A{l}_2{O}_3$ and $S{b}_2{O}_3$ are amphoteric and $B{i}_2{O}_3$ is basic.