Question

Assertion(A): Permanent hardness can be removed by adding zeolite to the hard water.

Reason(R): Zeolite decomposes and forms insoluble sodium zeolite.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true, but R is not the correct explanation of A.
• C. A is true and R is false.
• D. A is false and R is True.

Answer 1

The correct option is A

Both A and R are true and R is the correct explanation of A.

Explanations of correct option:

Assertion(A):

• The permanent hardness of water is due to the presence of ${\mathrm{Ca}}^{2+}$ and ${\mathrm{Mg}}^{2+}$salts.
• This can be removed by using zeolites.

So, this statement is true.

Reason(R):

• When sodium zeolite is added to hard water it gets decomposed and the sodium ion (${\mathrm{Na}}^{+}$) gets exchanged with ${\mathrm{Ca}}^{2+}$ and ${\mathrm{Mg}}^{2+}$ions.
• This permanently removes the hardness of the water.

So, the given statement for reason is also correct and it is the correct reason for the assertion.

Hence, the correct option is (A).