Calculate the bubble temperature at 85 kPa pressure for a binary liquid with
x1 = 0.40. The liquid solution is ideal. The saturation pressures are:
\[P^{sat} _1 = exp \left( 14.3\, -\, \frac{2945}{T+224} \right) \hspace{1cm} \]
\[P^{sat} _2 = exp \left( 14.2\, -\, \frac{2943}{T+209} \right) \hspace{5mm} \]
(temperature is in °C)