Question

two liquids A and B have vapour pressures in the ratio 3 ratio cannot be equal to 2 ratio 3 at a certain temperature at A and B form an ideal solution in the ratio of mole fractions of a to b in the vapour Phase 1 is to 3 then the mole fraction of a Hindi solution at the same temperature is​

Answer 1

pa = xa*Pa0 .....i)pb = xb*Pa0 .....ii)where pa and pb are the partial vapor pressure of A and B, xa xb are the mole fraction of A and B in the liquid and Pa0 and Pb0 are the vapor pressure of A and B.Also, pa = ya* P...iii)pb = yb *P ..........iv)where ya and yb are the mole fraction in vapour phase, and P is the total pressure.Taking ratio of i and ii, and substituting value of pa and pb from eq iii and iv we get ,ya/yb = (xa/xb)*(Pa0/Pb0)Substituting the values and solving we getxa = 1/3