A mixture of ethyl alcohol and propyl alcohol has a vapour pressure of `290mm`at `300K` .The vapour pressure of propyl alcohol is `200mm` .if the mole fraction of ethyl alcohol is `0.6` ,its vapour pressure (in mm)at the same temperature will be

Options

A. `350`
B. `300`
C. `700`
D. `360`

Answer

A

Explanation

`P_(m)=P_(A)+P_(B)`
`P_(A)^(@)X_(A)+P_(B)^(@)X_(B)`
`:. P_(m)=290mm,P_(B)^(gamma)=20mm,X_(A)=0.6,X_(B)`
`=1-0.6=0.4`
`:. 290=P_(A)^(@)xx0.6+200xx0.4`
`P_(A)^(gamma)=350mm`