Question

Generally, metallic oxides are basic and non-metallic oxides are acidic in nature. Solution of which of the following oxides in water will change the colour of blue litmus to red?

• A. Sulphur dioxide
• B. Magnesium oxide
• C. Iron oxide
• D. Copper oxide

Answer 1

Answer: (A)

Sulphur dioxide

The oxides of metal are basic in nature or in other words they react with acids to form salt and water. In the case of non-metals, they are acidic in nature to form acids when they dissolve in water.

When sulphur dioxide is dissolved in water sulphurous acid is formed. The reaction can be given as follows:

$S{O}_2+H_{2}O\to H_{2}S{O}_3$

The sulphurous acid turns blue litmus paper red.