# Problem: The ΔH°f of gaseous dimethyl ether (CH3OCH3) is −185.4 kJ/mol; the vapor pressure is 1.00 atm at −23.7°C and 0.526 atm at −37.8°C. (a) Calculate ΔH°vap of dimethyl ether.

###### FREE Expert Solution

Recall: The Clausius-Clapeyron Equation allows us to calculate the enthalpy of vaporization of a liquid using it's vapor pressures at different temperatures. It's given by:

where P1 and P2 are the vapor pressure of the liquid at temperatures T1 and T2, respectively, and R = 8.314 J/mol K.

###### Problem Details

The Δf of gaseous dimethyl ether (CH3OCH3) is −185.4 kJ/mol; the vapor pressure is 1.00 atm at −23.7°C and 0.526 atm at −37.8°C. (a) Calculate ΔH°vap of dimethyl ether.