Question

Permanent hardness of water cannot be removed by _______?

• A. Boiling
• B. Permutit method
• C. Ion exchange method
• D. Washing soda method

Answer 1

The correct option is A

Boiling

The explanation for the correct option:

Option (A): Boiling

• The permanent hardness of water is due to the presence of soluble salts of magnesium and calcium which are present in the form of chlorides and sulfides inside the water, and cannot be easily removed.
• The permanent hardness of the water can be easily removed by all the other methods given i.e the Permutit method, the Ion exchange resin method, and the washing soda method.
• However, the permanent hardness of water cannot be removed by physical methods i.e boiling, filtering, and distillation.

The explanation for the correct option:

Option (B): Permutit method

• The permanent hardness of water can be easily removed by the Permutit method.
• Hence, the given option is the incorrect option.

Option (C): Ion exchange method

• We can remove the Permanent hardness of water by the Ion-exchange method.
• Hence, the given option represents the incorrect answer.

Option (D): Washing soda method

• The permanent hardness of water can be removed by the Washing soda method.
• Thus, the given option corresponds to the incorrect answer.

Hence, the permanent hardness of water cannot be removed by boiling, option (A) is the correct answer.