\( = \,P_{Heptane}^o\) \(x_{\text {heptane}}+P_{Oc\tan e}^o\) \(x_{O c \tan e}\)
\(=105 \times \frac{25 / 100}{\frac{2}{100}+\frac{33}{114}}+45 \times \frac{35 / 114}{\frac{25}{100}+\frac{55}{114}}\)
\(=105 \times \frac{0.25}{0.25+0.3}+45 \times \frac{0.3}{0.25+0.3}\)
\(=\frac{105 \times 0.25}{0.55}+\frac{45 \times 0.3}{0.55}\)
\(=\frac{26.25+13.5}{0.55}=72\, k P a\)
(ઉપયોગ $R$ $=0.083\,L\,bar\,K ^{-1}\,mol ^{-1}$ )