Match the followi

1. causes scale - d. calcium bicarbonate

Hard water contains calcium bicarbonates. When it is boiled, the bicarbonates break and an insoluble carbonate are formed which deposits on the walls of the container.

2. basic oxide - a. calcium oxide

A basic oxide is an oxide that shows basic properties. It reacts with water to form a base to form a salt and water.

3. test for hardness of water - b. soap

Hard water contains calcium and magnesium bicarbonates. When soap is added to hard water, insoluble carbonates are formed.

4. acidic oxide - c. sulphur dioxide

Sulphur dioxide present in the atmosphere reacts with rain water to form sulphurous acid.

e. neutral oxide - f. does not react with water

Neutral oxides neither react with acids nor with bases.