Thermodynamic Properties of Key Organic Oxygen Compounds in the Carbon Range C1 to C4. Part 2. Ideal Gas Properties

Abstract

The ideal gas thermodynamic properties of forty-four key organic oxygen compounds in the carbon range C1 to C4 have been calculated by a statistical mechanical technique. The properties determined are the heat capacity (C○p), entropy {S○(T)−S○(0)}, enthalpy {H○(T)−H○(0)}, and Gibbs energy function {G○(T)−H○(0)}/T. The calculations have been performed, in most cases, over the temperature range 0 to 1500 K and at 1 bar. The contributions to the thermodynamic properties of compounds having internal- or pseudo- rotations have been computed by employing a partition function formed by the summation of the internal rotational or pseudorotational energy level for each rotor in the given molecule. These energy levels have been calculated by solving the wave equation using appropriate barrier heights, rotational constants, and potential functions for the given rotations. The thermodynamic properties have been calculated using a rigid-rotor and harmonic-oscillator molecular model for each species. The sources of molecular data and the selection of the values used in the calculation are described. The calculated C○p and {S○(T)−S○(0)} values are compared with experimental results where appropriate.