A `0.004M` solution of `Na_(2)SO_(4)` is isotonic with `0.010` M solution of glucose at same temperature . The apparent percentage dissociation of `NaSO_(4)` is :

Options

A. 0.25
B. 0.5
C. 75
D. 0.85

Answer

C

Explanation

`{:(Na_(2)SO_(4) ,hArr, 2Na^(+)+, SO_(4)^(2-)),((0.004-x),, 2x, x):}`
Since both solutions are isotonic, therefore, `0.004 + 2x = 0.01, x = 3 xx 10^(-3)`
`:.` % Dissociation `= (3 xx 10^(-3))/(0.004) xx 100 = 75`