Q21 / 125 · BITSAT 2015 · Chemistry
Which of the following is the most basic oxide?
- A$\mathrm{Sb}_{2} \mathrm{O}_{3}$
- Correct answerB$\mathrm{Bi}_{2} \mathrm{O}_{3}$
- C$\mathrm{SeO}_{2}$
- D$\mathrm{Al}_{2} \mathrm{O}_{3}$
Solution
More the oxidation state of the central atom (metal) more is its acidity. Hence $\mathrm{SeO}_{2}(\mathrm{O} . \mathrm{S} .$ of $\mathrm{Se}=+4)$ is acidic. Further for a given O.S., the basic character of the oxides increases with the increasing size of the central atom. Thus $\mathrm{Al}_{2} \mathrm{O}_{3}$ and $\mathrm{Sb}_{2} \mathrm{O}_{3}$ are amphoteric and $\mathrm{Bi}_{2} \mathrm{O}_{3}$ is basic.
Hence, the correct answer is option: 'B'.