Identify the metallic oxide which is amphoteric in nature?

The correct option is C

Zinc oxide

Explanation for correct option:

C) Zinc oxide

• The amphoteric compounds are compounds that can react with both acids as well as bases.
• Zinc oxide, is amphoteric because it reacts with both acids and bases to form salts.

Example: Zinc oxide reacts with Hydrochloric acid we get Zinc chloride and water.

ZnO(s) + 2HCl(aq) ⇢ ZnCl₂ (aq) + H₂O(aq)

Zinc oxide reacts with Sodium hydroxide(base) we get Sodium zincate and water.

ZnO(s) + 2NaOH (aq) ⇢ Na₂ZnO₂ (aq) + H₂O(aq)

Explanation for incorrect option:

A) Calcium oxide

• Calcium is alkaline earth metal because its oxides and hydroxides have an alkaline pH value when dissolved in water.
• Calcium oxide is not an amphoteric oxide, it is a basic oxide that reacts with the acid, salt and water are formed.
• When Calcium oxide reacts with Dilute hydrochloric acid to form Calcium chloride and water.

CaO(s) + 2HCl (aq) ⇢ CaCl₂ (aq) + H₂O(aq)

B) Barium oxide

• Barium oxide is basic. It react with water vapour at temperature 1443 to 1593 K to form gaseous Barium hydroxide(Ba(OH)₂)

BaO(s) + H₂O (v) ⇢ Ba(OH)₂ (g)

D) Copper(II) oxide.

• Copper(II) oxide is basic in nature. It reacts with hydrochloric acid we get Copper chloride and water.

CuO(s) + 2HCl (aq) ⇢ CuCl₂ (aq)+ H₂O(aq)

There fore Zinc oxide is amphoteric.