A solution has `1:4` mole ratio of pentane to hexane . The vapour pressure of pure hydrocarbons at `20^@C`are `440` mmHgfor pentane and `120`mmHg for hexane .The mole

Options

A. `0.786`
B. `0.478`
C. `0.549`
D. `0.200`

Answer

B

Explanation

`P=P_(C_(5)H_(12))^(O)xxX_(C_(5)H_(12))+P_(C_(6)H_(14))^(O)xxX_(C_(6)H_(14)),`
`p=440xx(1)/(5)+120xx(4)/(5)=(920)/(5)=184 y_(C_(5)H_(12))=(P_(C_(5)H_(12)))/(P_(t))`
Now,`Y_(C_(5)H_(12))=(88)/(184)=0.478`