If `alpha` is the degree of dissociation of `na_(2)SO_(4)` the vant of Hoff's factor (i) used for calculating the molecular mass is-

Options

A. `1+2alpha`
B. `1-2alpha`
C. `1-alpha`
D. `1+alpha`

Answer

A

Explanation

`Na_(2)SO_(4) hArr 2Na^(+)+SO_(4)^(2-)` van't hoff factor. `i=[1+(y-1)alpha]`
Where y is the number of ions from one mole solutions of dissociation
`:. (i=1+2alpha)`