Question

Amphoteric oxides react only with acids to form salt and water.

• A. True
• B. False

Answer 1

The correct option is B False

• Amphoteric oxides are defined as metal oxides that react with both acids as well as bases to create salts and water.
• Base Sodium hydroxide($\mathrm{NaOH}$) react with a metal oxide $\mathrm{ZnO}$ to form salt Sodium zincate(${\mathrm{Na}}_2{\mathrm{ZnO}}_2$)and water.
• Chemical equation:

$\underset{\mathrm{Sodium}\mathrm{hydroxide}}{2\mathrm{NaOH}\left(\mathrm{aq}\right)}+\underset{\mathrm{Zinc}\mathrm{oxide}}{\mathrm{ZnO}\left(\mathrm{aq}\right)}\to \underset{\mathrm{Sodium}\mathrm{zincate}}{{\mathrm{Na}}_2{\mathrm{ZnO}}_2\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

• Sulphuric acid(${\mathrm{H}}_2{\mathrm{SO}}_4$) reacts with an amphoteric metal oxide $\mathrm{ZnO}$ to form salt Zinc sulfate and water.
• Chemical equation:

$\underset{\mathrm{Zinc}\mathrm{oxide}}{\mathrm{ZnO}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulphuric}\mathrm{acid}}{{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)}\to \underset{\mathrm{Zinc}\mathrm{sulphate}}{{\mathrm{ZnSO}}_4\left(\mathrm{aq}\right)}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

Therefore the given statement is false.