A 0.004 M solution of sodium sulphate is isotonic with .010 M solution of glucose. The apparent percentage dissociation sodium sulphate is

Options

A. `25%`
B. `50%`
C. `75%`
D. `85%`

Answer

C

Explanation

Hint : `pi_("sod. sulphate")=pi_("glucose")`
`underset(1-alpha)(Na_2SO_4)rarrunderset(2alpha)(2Na^(+))+underset(alpha)(SO_4^(2-))`
`i=1+2alpha=2.5`
`alpha = 0.75 ` or 75% dissociation