The normal boiling point (1 atm or 760 mmHg) of ether is 307…

The normal boiling point (1 atm or 760 mmHg) of ether is 307.8 K. Calculate the temperature at which its vapor pressure is exactly half of that at its normal boiling point. The heat of vaporization (ΔHvap) for ether is 26.69 kJ/mol. Round to whole number for answer. (R = 8.314 J/K × mol)