Vapour pressure of `C CL_(4)` at `25^@C` is `143` mmHg 0.05g of a non-volatile solute (mol.wt.=`65`)is dissolved in `100ml C CL_(4)`. find the vapour pressure of the solution (density of `C CL_(4)=158g//cm^2`)

Options

A. 94.39mm
B. 141.93mm
C. 134.44mm
D. 199.34mm

Answer

B

Explanation

Relative lowering in vapour pressure,
`(p^(@)-p_(s))/(p_(@))=(wxxM)/(mxxW)`
`(143-p_(s))/(143)=(0.5)/(65)xx(154)/(1.58xx100)" "[because"molecular weight of "C Cl_(4)=154 " and weight = density " xx" volume"]`
`143-p_(s)=1.07rArrp_(s)=141.93mm`