Question

Which of the following is not applicable for softening hard water?

• A. Zeolite
• B. Calgon
• C.
• D.

Answer 1

The correct option is C

Permanent hardness is due to the chlorides and sulphates of $C{a}^{2+}$ and $M{g}^{2+}$ while temporary hardness is due to bicarbonates of $C{a}^{2+}$ and $M{g}^{2+}$. Water hardness can be treated using any of these: Zeolite/Permutit, Calgon and $N{a}_{2}C{O}_3$.


$MgC{l}_2$ is very soluble in water and it causes permanent hardness.