Use the following data to determine the molar heat of vaporization of chlorine (R = 8.314 J/K mol). T (°C): -84.5, -71.2, -47.3; P (mmHg): 40.0, 100.0, 400.0.
(a) 20 kJ/mol
(b) 25 kJ/mol
(c) 30 kJ/mol
(d) 35 kJ/mol