`1.0 g` of non-electrolyte solute dissolved in `50.0 g` of benzene lowered the freezing point of benzene by `0.40 K`. The freezing point depression constant of benzene is `5.12 kg mol^(-1)`. Find the molecular mass of the solute.

Options

A. `256gmol^(-1)`
B. ` 2.56g mol^(-1)`
C. `512 xx 10^(3) g mol^(-1)`
D. `2.56 xx 10^(4) g mol^(-1)`

Answer

A

Explanation

`M_(B) =( K_(f) xxW_(B) xx 1000)/( Delta T_(f) xxW_(A))`
`= ( 5.12 xx 1 xx 1000)/( 0.4 xx 50) =256 `