The molecular formula of a commercial resin used for exchanging ions in water softening is C8H7SO3Na (molecular weight : 206). What would be the maximum uptake of Ca2+ ions by the resin when expressed in mole per gram resin?

# The molecular formula of a commercial resin used for exchanging ions in water softening is (molecular weight : 206). What would be the maximum uptake of ions by the resin when expressed in mole per gram resin?

1. A

1/103

2. B

1/206

3. C

2/309

4. D

1/412

Register to Get Free Mock Test and Study Material

+91

Live ClassesRecorded ClassesTest SeriesSelf Learning

Verify OTP Code (required)

### Solution:

The exchanging reaction is $2{\mathrm{C}}_{8}{\mathrm{H}}_{7}{\mathrm{SO}}_{3}\mathrm{Na}+{\mathrm{Ca}}^{2+}\to {\left({\mathrm{C}}_{8}{\mathrm{H}}_{7}{\mathrm{SO}}_{3}\right)}_{2}\mathrm{Ca}+2{\mathrm{Na}}^{+}$ For one mole of  ions, two moles of resin is required. Thus, the maximum uptake of  ions will be $1\mathrm{mol}{\mathrm{Ca}}^{2+}/2\mathrm{mol}$ resin =1 mole  resin$\equiv \left(1/412\right)\mathrm{mol}{\mathrm{Ca}}^{2+}/\mathrm{g}$ of resin