What is the nature of non-metallic oxides? How will you test it?

Non-metallic oxides are oxides of non-metals.

For example, sulphur and carbon are both non-metals. They react with oxygen to form sulphur dioxide and carbon dioxide.

These oxides are acidic in nature.

Example: Sulphur dioxide and carbon dioxide react with water and Carbonic acid (H₂CO₃) and sulphuric acid (H₂SO₄).

Test: They form an acidic solution when dissolved in water, turning the blue litmus solution into red colour.

[Extra information: Litmus is a water-soluble mixture of different dyes extracted from lichens. It is often absorbed onto filter paper to produce one of the oldest forms of pH indicator known as Litmus paper.

It is used to test materials for acidity and basicity.

1. Blue litmus paper turns red under acidic conditions. 

2. Red litmus paper turns blue under alkaline conditions.

3. Neutral litmus paper is purple in colour.]