Question

Which of the following is the most basic oxide?

• A. $Sb _{2} O _{3}$
• B. $Bi_2O_3$
• C. $SeO_2$
• D. $Al_2O_3$

Answer 1

Answer: (B)

$Bi_2O_3$

Answer 2

$Bi _{2} O _{3}$ is the most basic oxide.
More the oxidation state of the central metal atom, more is its acidity. Hence , $SeO _{2}$ ($O.S$ 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, $Al _{2} O _{3}$ and $Sb _{2} O _{3}$ are amphoteric and $Bi _{2} O _{3}$ is basic.