What is its molar heat of vaporization in kilojoules per mole if its vapor pressure at 20°C is 11.0 torr?

H. vap = 6.544 kJ/mol

Explanation:

Clausius-Clapeyron Equation

In P = H. vap / RT where T = 20 + 273 = 293K

H. vap = In P (RT) = In 11 (8.314 x 293) = 6543.861 J/mol = 6.544 kJ/mol