Question

Salts of calcium and magnesium like ___________ cause hardness of water.

• A. bicarbonates
• B. chlorides
• C. sulphates
• D. phosphates

Answer 1

Answer: (A), (B), (C)

The correct options are
A bicarbonates
B chlorides
C sulphates

Hard water is the water that contains soluble salts of bivalent ions like calcium and magnesium principally in the form of bicarbonates, chlorides, and sulfates. Water is softened on a small scale by the addition of phosphates, together with sodium carbonate (washing soda) which separates the calcium and magnesium as white precipitates of their respective phosphates.

Therefore option $A,B,C$ are correct