Question

Assertion (A): Hard water gives easy lather with soap.
Reason (R): Salts of calcium and magnesium react with soap to form insoluble salts.

• A. (A) and (R) both are correct and (R) is the correct explanation of (A).
• B. (A) and (R) both are correct but (R) is not the correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Answer 1

The correct option is D (A) is not correct but (R) is correct.

Hard water contains dissolved chlorides, sulphates and bicarbonates of calcium or magnesium. It does not lather with soap because the salts of calcium and magnesium react with soap to form insoluble precipitate of scum.