ABSTRACT
This chapter discusses evaluation of properties of two phase mixtures as well as gases. In the case of the former, although the development is for water, there is no loss of generality since the concepts and ideas carry over without any change to two phase mixtures of other substances. In thermodynamics, in addition to the equation of state, an equation relating the internal energy to other measurable properties. The internal energy, strictly speaking, is a function of two thermodynamic properties, namely, temperature and specific volume. From a molecular perspective, it can be seen intuitively that the internal energy will depend on the number of modes in which energy can be stored by the molecules and the amount of energy that can be stored in each mode. For monatomic gases, the atoms have the freedom to move in any of the three coordinate directions.
