A solution containing 10 g per `dm^(3)` of urea (molecular mass = 60 g `mol^(–1)`) is isotonic with a 5% solution of a nonvolatile solute. The molecular mass of this nonvolatile solution is:

Options

A. `350gmol^(-1)`
B. `200gmol^(-1)`
C. `250gmol^(-1)`
D. `300gmol^(-1)`

Answer

D

Explanation

`C_(1)RT=C_(2)RT` (`C_(1) and C_(2)` in mole/litre)
`(10)/(60)=(50)/(m)`
`implies m=300`.