Question

Which of the following is an amphoteric oxide?

• A. Na$_2$O.
• B. MgO.
• C. Al$_2$O$_3$.
• D. P$_2$O$_5$.

Hint:

Al$_2$O$_3$ is found in bauxite and is used in aluminum extraction.

Answer 1

The Correct Option is C

An amphoteric oxide is one that reacts with both acids and bases. Aluminum oxide (Al$_2$O$_3$) exhibits this behavior: \[ Al_2O_3 + 6HCl \rightarrow 2AlCl_3 + 3H_2O \] \[ Al_2O_3 + 2NaOH + 3H_2O \rightarrow 2Na[Al(OH)_4] \]