To use the macroscopic balances intelligently, it is necessary to use information about interphase transport that comes from the equations of change. To use the equations of change, we need the transport properties, which are described by various molecular theories. Therefore, from a teaching point of view, it seems best to start at the molecular level and work upward toward the larger systems.
All the discussions of theory are accompanied by examples to illustrate how the theory is applied to problem solving, Then at the end of each chapter there are problems to provide extra experience in using the ideas given in the chapter. The problems are grouped into four classes:
- Class A: Numerical problems, which are designed to highlight important equations in the text and to give a feeling for the orders of magnitude.
- Class B: Analytical problems that require doing elementary derivations using ideas mainly from the chapter.
- Class C: More advanced analytical problems that may bring ideas from other chapters or from other books.
- Class D: Problems in which intermediate mathematical skills are required.