Question

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

Answer 1

Correct Answer - A
`P_(m) = P_(A)+P_(B) = P_(A)^(@).X_(A)+P_(B)^(@).X_(B)` ltbr. `290 = P_(A)^(@) xx 0.6 + 200 xx 0.4`
`P_(A)^(@) = 350 mm`