devarshi-dt-logo

Question:

Liquid M and liquid N form an ideal solution. The vapour pressures of pure liquids M and N are 450 and 700 mm Hg, respectively, at the same temperature. Then correct statement is: (x_M= Mole fraction of M in solution; x_N= Mole fraction of N in solution; y_M= Mole fraction of M in vapour phase; y_N= Mole fraction of N in vapour phase)

xMxN>yMyN

xMxN<yMyN

xMxN=yMyN

(xM-yM)<(xN-yN)

Solution:

Correct option is C.
xMxN>yMyN
Since PNo > PMo, so N is more volatile than M.
∴ yN > xN and xM > yM
Multiply we get yN × xM > xN × yM
i.e. xMxN = yMyN