Question

Which anions are responsible for water hardness ?

Answer 1

1. Hard water contains high water content.
2. It contains excess of limestone or chalk which is made up of carbonates, bicarbonates or sulphates of calcium and magnesium.
3. There can be temporary or permanent hardness.
4. Temporary hardness is caused by bicarbonates of magnesium and calcium.
5. While permanent hardness is caused due to presence of soluble chlorides and sulphates of calcium and magnesium.
6. Therefore, ions of calcium and magnesium are responsible for water hardness and the anions are hence chlorides and sulphates.