Question

Using the Clausius-Clapeyron equation,calculate the heat of vaporization for the vapour pressure of water at 85 degrees celcius is 0.5atm and at 95 degrees celcius is at 0.9atm.

Answer 1

$ln(\frac{P_1}{P_2})=(\frac{H_{vap}}{R})(\frac{1}{T_2}-\frac{1}{T_1})$

$ln(\frac{0.5}{0.9})=(\frac{H_{vap}}{R})(\frac{1}{368}-\frac{1}{358})$

$(\frac{H_{vap}}{R})= 3363.06$

$(H_{vap})= 3363.06×8.3145=27962.16 J mol$