Question

7. At 20 °C, the vapour pressure of pure liquid A is 22 mmHg and that of pure liquid B is 75 mm Hg. What is the composition
of the solution of these two components that has a vapour pressure of 48.5 mm Hg at this temperature (assume ideal
behaviour)?​

Answer 1

Answer:

the given values are

Pa°=22mmHg, PB°=75mmHg,Ptotal=48.5m

let xA and XB are the mole fractions if liquids A and B , respectively, in solution, then

PA=PA°XA=22XA

PB=PB°XB=PB°(1-XA)=75(1-XA)

ptotal=PA+PB=22XA+75(1-xA)=48.5

XA=0.5 and xB=1-x(A)=0.5