Thermal capacities of organic compounds

To estimate the thermodynamic properties of pure fluid organic compounds, it is first necessary to know the corresponding properties of the perfect gas of the same chemical formula as the compound in question, at the same temperature and pressure.

The corrective term to be added to these values to obtain the real value sought is called residualproperty, and its estimation is based either on knowledge of the equation of state of the fluid, or on the application of the method of corresponding states.

The following table provides the basis for calculating isobaric molar heat capacities as a function of temperature for organic compounds that are perfect gases. The numbers of these compounds are those of the table in the article which gives molar masses, temperatures and normal melting and boiling enthalpies.

The final estimates obtained are excellent for non-polar or slightly polar molecules, and satisfactory for others.