OVERVIEW

Thermochemistry is an important part of explosive chemistry: it provides information on the type of chemical reactions, energy changes, mechanisms and kinetics which occur when a material undergoes an explosion. This chapter will carry out theoretical thermochemical calculations on explosive parameters, but it must be noted that the results obtained by such calculations will not always agree with those obtained experimentally, since experimental results will vary according to the conditions employed.

When an explosive reaction takes place, the explosive molecule breaks apart into its constituent atoms. This is quickly followed by a rearrangement of the atoms into a series of small, stable molecules. These molecules are usually water (H ₂O), carbon dioxide (CO ₂), carbon monoxide (CO) and nitrogen (N ₂). There are also molecules of hydrogen (H ₂), carbon (C), aluminium oxide (Al ₂O ₃), sulfur dioxide (SO ₂), etc., found in the products of some explosives. The nature of the products will depend upon the amount of oxygen available during the reaction. This supply of oxygen will depend in turn upon the quantity of oxidizing atoms which are present in the explosive molecule.