The Entropy of Formic Acid. The Heat Capacity from 15 to 300°K. Heats of Fusion and Vaporization
- 1 February 1941
- journal article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 9 (2), 163-168
- https://doi.org/10.1063/1.1750869
Abstract
The heat capacity of solid and liquid formic acid has been measured from 15 to 300°K. The melting point is 281.40°K (0°C=273.10°K). The heat of fusion is 3031 cal. mole‐1 and the heat of vaporization at 298.10°K is 4754 cal. mole‐1. (1 mole=46.0260 grams.) The vapor pressure at 298.10°K is 4.31 cm of mercury. From the third law of thermodynamics and the calorimetric data the entropy has been calculated. To the value obtained from the calorimetric measurements an entropy of R/2 ln 2, due to the random orientation of hydrogen bonds in the solid which has been predicted by Pauling, has been added. This gives 31.51 cal. deg.‐1 mole‐1 for the entropy of the liquid at 298.10°K and 47.46 for the entropy of 46.0260 grams of gas, P=4.31 cm, in equilibrium with the liquid at 298.10°K. These are the values that should be used in thermodynamic calculations.Keywords
This publication has 18 references indexed in Scilit:
- Carbonyl Sulfide. The Heat Capacity, Vapor Pressure, and Heats of Fusion and Vaporization. The Third Law of Thermodynamics and Orientation Equilibrium in the SolidJournal of the American Chemical Society, 1937
- The Entropy of Deuterium Oxide and the Third Law of Thermodynamics. Heat Capacity of Deuterium Oxide from 15 to 298°K. The Melting Point and Heat of FusionJournal of the American Chemical Society, 1936
- The Entropy of Water and the Third Law of Thermodynamics. The Heat Capacity of Ice from 15 to 273°K.Journal of the American Chemical Society, 1936
- Additions and Corrections - The Heat Capacity and Entropy of Carbon Monoxide. Heat of Vaporization. Vapor Pressure of Solid and Liquid. Free Energy to 5000 degrees K. from Spectroscopic DataJournal of the American Chemical Society, 1933
- THE HEAT CAPACITY AND ENTROPY OF CARBON MONOXIDE. HEAT OF VAPORIZATION. VAPOR PRESSURES OF SOLID AND LIQUID. FREE ENERGY TO 5000°K. FROM SPECTROSCOPIC DATAJournal of the American Chemical Society, 1932
- THE ENTROPY OF HYDROGEN AND THE THIRD LAW OF THERMODYNAMICS THE FREE ENERGY AND DISSOCIATION OF HYDROGENJournal of the American Chemical Society, 1930
- THE VAPOR PRESSURE AND HEATS OF FUSION AND VAPORIZATION OF FORMIC ACIDJournal of the American Chemical Society, 1930
- THE VAPOR DENSITY AND SOME OTHER PROPERTIES OF FORMIC ACIDJournal of the American Chemical Society, 1928
- THE ENTROPY OF HYDROGEN CHLORIDE. HEAT CAPACITY FROM 16°K. TO BOILING POINT. HEAT OF VAPORIZATION. VAPOR PRESSURES OF SOLID AND LIQUIDJournal of the American Chemical Society, 1928
- THE ULTRAVIOLET ABSORPTION SPECTRUM OF FORMIC ACIDJournal of the American Chemical Society, 1926