Question

The empirical formula of a commercial ion exchange resin is $C_8{H}_{7}S{O}_{3}Na(M.M=206)$. The resin can be used to soften water according to the reaction:
$C{a}^{2+}+2C_8{H}_{7}S{O}_{3}Na\to Ca(C_8{H}_{7}S{O}_3{)}_2+2N{a}^{+}$
What would be the maximum uptake of $C{a}^{2+}$ by the resin expressed in $\text{mol/g}$ of resin?

• A. $0.00243$
• B. $0.0243$
• C. $0.243$
• D. $0.0048$

Answer 1

The correct option is A $0.00243$

According to the reaction:
$C{a}^{2+}+2C_8{H}_{7}S{O}_{3}Na\to Ca(C_8{H}_{7}S{O}_3{)}_2+2N{a}^{+}$

2 mol of the resin requires 1 mol of $C{a}^{2+}$ ions.

$(2\times 206\text{g})$ of the resin requires 1 mol of $C{a}^{2+}$ ions.

So, $1\text{g}$ of the resin requires $=\frac{1}{2\times 206}\times 1=0.00243$ mol of $C{a}^{2+}$ ions.