Question

Soap forms insoluble precipitates with the calcium and magnesium ions in hard water.

• A. True
• B. False

Answer 1

The correct option is A True

Soaps are sodium or potassium salts of long chains of carboxylic acids. In hard water, the sodium ions separate and the carbon chain reacts with the calcium and magnesium salts. The calcium and magnesium salts of carboxylic acids are insoluble in water, hence, they form precipitates. So there are no hydrophilic ends. This is the reason, soaps are less effective when used in hard water.