Question

Which of the following options are true regarding metallic and non-metallic oxides?

• A. Nonmetallic oxides are basic in nature
• B. Metallic oxides are acidic in nature
• C. Nonmetallic oxides are acidic in nature
• D. Metallic oxides are basic in nature

Answer 1

Answer: (C), (D)

The correct options are
C Nonmetallic oxides are acidic in nature
D Metallic oxides are basic in nature

Non-metallic oxides are acidic in nature and metallic oxides are basic in nature. This is because the oxides of metals like magnesium oxide ($\text{MgO}$) or calcium oxide ($\text{CaO}$) form hydroxides in their aqueous solutions. For example:

${\text{K}}_2\text{O}\text{(aq)}+{\text{H}}_2\text{O}\text{(aq)}⟶2\text{KOH}\text{(aq)}$

When non-metallic oxides react with water, they form acidic substances which dissociate into their constituent ions in water. They give ${\text{H}}^{+}$ ions in their aqueous solutions forming acids. For example:

${\text{CO}}_2\text{(g)}+{\text{H}}_2\text{O}\text{(aq)}⟶{\text{H}}_2{\text{CO}}_3\text{(aq)}$