Barry Sturman
ABSTRACT: This is the first in a series of articles presenting an introductory outline of chemical thermodynamics and chemical kinetics, with emphasis on those aspects of particular relevance to pyrotechnics. A brief comment on the molecular theory of matter is followed by a discussion of basic mechanics to introduce the concepts of work and energy. The non-conservation of mechanical energy leads to the idea of heat as a form of energy, and to the Law of Conservation of Energy. The concepts of temperature and thermal equilibrium are then introduced. An introduction to thermodynamic systems, thermodynamic states and state functions is presented. The first Law of Thermodynamics is introduced as a statement of the Law of Conservation of Energy in terms of changes in internal energy, heat and work. The enthalpy is shown to be a useful thermodynamic state function; the enthalpy change in a process corresponds to the heat ransferred between a system and its surroundings at constant pressure. Calculations of the heat transferred in chemical reactions are demonstrated. A Table of standard enthalpies of formation of a range of pyrotechnically interesting materials is included for use in such calculations.
Keywords: thermodynamics, thermochemistry, energy, heat, flash powder
Ref: JPyro, Issue 9, 1999, pp29-50
(J9_29)
© Journal of Pyrotechnics and CarnDu Ltd
