Answer
See the answer below.
Work Step by Step
a) $70.3°C$, because that's the temperature at which the vapor pressure equals the atmospheric pressure.
b)
Performing a regression, we find:
$ln\ P=-3881.4/T_K+17.94$
Solving for the temperature:
$250\ mmHg: 39.5°C$
$650\ mmHg: 65.5°C$
c) From the Clausius-Clapeyron equation, it follows:
$\Delta H_v=-3881.4\ K×0.008314\ kJ/mol.K=32.27\ °C$
