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 chain carboxylic acid. In hard water, the sodium and carboxylate ions separate and the carboxylate ion reacts with the calcium and magnesium salts in the hard water to form precipitates which are insoluble in water. So there are no hydrophilic ends. This is the reason, soaps are less effective when used in hard water.