Heat capacity of hydrofluoric acid and (hydrofluoric acid + 2-methylpropane) by temperature-pulse calorimetry

Heat capacities of anhydrous liquid hydrofluoric acid and of HF saturated with 2-methylpropane are reported. The heat capacity of slightly compressed liquid HF is (2.66 and 2.80) J·g-1·K-1 at (25.1 and 45.9) °C, respectively. The heat capacity of liquid HF slightly compressed and saturated at 24 °C with 2-methylpropane (3.7 mass %) is 2.58 J·g-1·K-1 at 24.3 °C. Accuracy is within 2%. These are the first available data for the heat capacity of liquid HF above its normal boiling point. A temperature-pulse calorimeter is described.