For a dilute solution containing `2.5 g` of a non-volatile non-electrolyte solution in `100g` of water, the elevation in boiling point at `1` atm pressure is `2^(@)C`. Assuming concentration of solute is much lower than the concentration of solvent, the vapour pressure (mm of `Hg)` of the solution is:
(take `k_(b) = 0.76 K kg mol^(-1))`

Options

A. 724
B. 740
C. 736
D. 718

Answer

A

Explanation

`M_(2)=(1000k_(f)W_(2))/(W_(1)xxDeltaT_(f))=(1000k_(f)W_(2)')/(W_(1)'M_(2)')`
`or (M_(2))/(W_(1)')=(W_(1))/(W_(2))xxM_(2)=(0.50)/(100)xx(200)/(0.10)xx100`
`=1000`