A commercial ion-exchange resin used for water softening has the molecular formula C_ 8 H_ 7 SO_ 3 Na (Molar Mass = 206). Determine the maximum uptake of Ca^ 2+ ions by this resin in moles per gram of resin.

Home › MCQs › EEJ MAIN Chemistry › Question #7146

EEJ MAIN Chemistry QUESTION #7146

Question 1

A commercial ion-exchange resin used for water softening has the molecular formula $C_{8}H_{7}SO_{3}Na$ (Molar Mass $= 206$). Determine the maximum uptake of $Ca^{2+}$ ions by this resin in moles per gram of resin.

$\frac{1}{103}$
$\frac{1}{206}$
$\frac{2}{309}$
$\frac{1}{412}$✔️

Correct Answer Explanation

The ion exchange reaction is: $2RNa + Ca^{2+} \rightarrow R_{2}Ca + 2Na^{+}$.

$2$ moles of resin ($2 \times 206\text{ g}$) react with $1$ mole of $Ca^{2+}$.
Total mass of resin = $412\text{ g}$.
Uptake per gram = $\frac{1\text{ mole } Ca^{2+}}{412\text{ g resin}}$.

Thus, the maximum uptake is $\frac{1}{412}\text{ mol/g}$.

More Options