Question

When hydrated sodium aluminum silicate, which is zeolite, is treated with hard water, the sodium ions are exchanged with :

• A. $C{a}^{+}$
• B. $O{H}^{-}$ions
• C. $M{g}^{2+}$ions
• D. $Si{O}_4^{4-}$

Answer 1

The correct option is C $M{g}^{2+}$ions

When hydrated sodium aluminum silicate (which is zeolite), is treated with hard water, the sodium ion are exchange with $C{a}^{2+}$ and $M{g}^{2+}$ ions.
$N{a}_{2}Ze+M^{2+}\to MZe+2N{a}^{+}$
Here, $N{a}_{2}Ze$ is hydrated sodium aluminum silicate (which is zeolite), and $MZe$ is exhausted zeolite.
Exhausted zeolite can be regenerated by passing of $10\%$ $NaCl$ solution.