Thermodynamics

Abstract

Thermodynamics is said not to require a model. The reason for this is that in the area of thermodynamics, relationships between work and energy and the conversion of one to the other are studied. Therefore, the net result, i.e., how much energy or how much work is produced, is the desired information and not how many molecules reacted or explicitly an exact understanding of the reaction path. For example, the heat of melting, which is an endothermic process, can be obtained with the value expressed as joules per gram. Also, the heat of solution, which can be either endothermic or exothermic, has its value expressed as joules per gram. In both of these examples the results do not depend on knowledge of the exact number of molecules melting or dissolving or other interactions which can be occurring, such as solvation, but rather only the initial and final states. This is not to say that a model for the system is not useful when trying to understand what is occurring, only that it is not necessary to have a model for an equilibria in order to obtain a value for an equilibrium constant using thermodynamic measurements.