ABSTRACT
The subject of chemical thermodynamics applies to fixed mass and flowing systems, just as in the case of fixed composition systems. Thermodynamics enables us to calculate the energetics of system changes in composition. The subject of thermodynamics is only concerned with beginning and end thermodynamic states for a system, with no concern for the process path between them. In any event, the reader should recall from thermodynamics that the enthalpy is the most natural variable for treating steady flow systems. One of the most important calculations chemical thermodynamics allows us to make is that of the adiabatic flame temperature. The thermodynamics are not changed, however, if we had considered the hydrogen and fluorine to be initially separated by a thin barrier which is then broken to initiate mixing and reaction. Fortunately, thermodynamics also tells us how to calculate which species are present, and in what abundance.
