Question

What are some examples of amphoteric oxides?

Answer 1

Amphoteric oxides

• Amphoteric oxides are oxides that have both acidic and basic properties or that can react with both acid and base.
• Some examples of amphoteric oxides are Zinc oxide$\left(\mathrm{ZnO}\right)$ , Aluminium oxide $\left({\mathrm{Al}}_2{\mathrm{O}}_3\right)$,and Sodium oxide $\left({\mathrm{Na}}_2\mathrm{O}\right)$, Gallium oxide$\left({\mathrm{Ga}}_2{\mathrm{O}}_3\right)$.

Amphoteric nature of Zinc oxide:-

Acidic nature

• Zinc oxide $\left(\mathrm{ZnO}\right)$ reacts with hydrochloric acid $\left(\mathrm{HCl}\right)$, formation of zinc chloride $\left({\mathrm{ZnCl}}_2\right)$and water$\left({\mathrm{H}}_2\mathrm{O}\right)$ takes place.
• $\mathrm{ZnO}\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Basic nature

• Zinc oxide$\left(\mathrm{ZnO}\right)$ reacts with Sodium hydroxide$\left(\text{NaOH}\right)$, formation of Sodium zincate $\left({\text{Na}}_2{\text{ZnO}}_2\right)$and water$\left({\mathrm{H}}_2\mathrm{O}\right)$ takes place.
• $\mathrm{ZnO}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{s}\right)\to {\mathrm{Na}}_2{\mathrm{ZnO}}_2\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$