The vapour pressure lowering caused by addition of 100 g of sucrose (molecular mass = 342) to 1000 g of wate,if the vapour pressure of pure water at `25^(@)C` is 23.8mm Hg,is

Options

A. 1.25 mm Hg
B. 0.125 mm H g
C. 1.15 mm Hg
D. 00.12 mm Hg

Answer

B

Explanation

`(P^(0)-P)/(P^(0)) = ( W_(B)M_(A))/(M_(B)W_(A))`
`(P^(0)-P) =(100xx 18 xx 23.8 )/( 342 xx 1000)`
`( P^(0) - P) = 1.25 mm Hg`