\(x_{B}=1-0.6=0.4, P=290\)
\(P=P_{A}+P_{B}=P_{A}^{\circ} x_{A}+P_{B}^{\circ} x_{B}\)
\(\Rightarrow 290=P_{A}^{\circ} \times 0.6+200 \times 0.4\)
\(\therefore \quad P_{A}^{\circ}=350\, \mathrm{mm}\)
(આપેલઃ ઈથેનોલનું ઠારણ બિંદુ $156.0\, K$, ઈથેનોલની ધનતા $0.80\, g\, cm ^{-3}$, ઈથેનોલનો ઠારબિંદુ અવનયન અચળાંક $2.00\, K\, kg \,mol ^{-1}$ )