For a solution of acetone in chloroform, Henry's law constant is 150 torr at a temperature of 300 K. (a) Calculate the vapour pressure of acetone when the mole fraction is 0.12. (b) Assuming that Henry's law is applicable over sufficient range of composition to make the calculation valid, calculate the composition at which Henry's law pressure of chloroform is equal to Henry's law pressure of acetone at 300 K. (Henry's law constant for chloroform is 175 torr.)

Explanation

a.The given value are
`K_(H)`= 150 torr , `chi_("acetone") = 0.12`
Using Henry's law equation
`P=K_(H)chi`, on substituting all values
P= (150 torr ) (0.12) = 18.0 torr
(b.) Here P=18.0 torr, and `K_(H) = 175.0` torr
`:. chi_("acetone") = P/K_(H) = 18.0 "torr"/175.0 "torr" = 0.103`