Ethanol (C2H5OH) melts a - 144 oC and boils at 78 °C. The enthalpy of fusion of ethanol is 5.02 kj/mol, and its enthalpy of vaporization is 38.56 kj/mol. The specific heats of solid and liquid ethanol are 0.97j/g - k and 2.3 j/g - K, respectively.
(a) How much heat is required to convert 42.0 g of ethanol at 35 °C to the vapor phase at 78 °C?
(b) How much heat is required to convert the same amount of ethanol at - 155 oC to the vapor phase at 78 °C?