Question

In the removal of permanent hardness of water by permutit process, \(Na^+\) ions of permutit are exchanged with which ions of water?

• A. \(K^+,\ Ba^{2+}\)
• B. \(Fe^{2+},\ K^+\)
• C. \(Ca^{2+},\ Mg^{2+}\)
• D. \(Zn^{2+},\ Cu^{2+}\)

Hint:

Hardness of water is mainly due to \(Ca^{2+}\) and \(Mg^{2+}\) ions.

Answer 1

The Correct Option is C

Step 1: Permanent hardness of water is mainly due to soluble salts of calcium and magnesium.

Step 2: The important hardness-producing ions are: \[ Ca^{2+} \] and \[ Mg^{2+} \]

Step 3: In the permutit process, sodium zeolite exchanges its \(Na^+\) ions with \(Ca^{2+}\) and \(Mg^{2+}\) ions.

Step 4: This removes calcium and magnesium ions from hard water.

Step 5: Hence, \(Na^+\) ions are exchanged with: \[ Ca^{2+},\ Mg^{2+} \] \[ \boxed{Ca^{2+},\ Mg^{2+}} \]