Methanol: Heat Capacity, Enthalpies of Transition and Melting, and Thermodynamic Properties from 5–300°K

Abstract
Thermal properties of methanol were studied by adiabatic calorimetry. The first‐order nature of the phase transition at 157.4°K with an entropy increment of 0.97 cal mole−1⋅°K−1 was confirmed. The heat capacity of the crystalline phase stable just below the triple point was defined and shown to be extremely sensitive to impurity. No evidence for a second previously‐reported phase transition could be detected. The standard entropy (S°)(S°) and Gibbs energy function (− [G° − H°0] / T)(−[G°−H°0]∕T) for the liquid at 298.15°K are 30.40 and 15.18 cal mole−1⋅°K−1, respectively. The proposed classification of methanol as a plastic crystal on the basis of its small entropy of melting (4.38 cal mole−1⋅°K−1) is considered with respect to hydrogen bonding in the liquid phase