Thermochemistry is the study of heat released or absorbed by chemical reaction. It is a branch of thermodynamics and is used by a wide range of scientists and engineers. For example, biochemists use thermochemical understand bioenergetics, while applying chemical engineers in the design of manufacturing plants. Chemical reactions involving the conversion of a set of substances collectively called “reactive” to a group of substances collectively called “products”. In the following balanced chemical reaction reactants are methane, CH4 (g) and molecular oxygen gas, O2 (g), and the products are carbon dioxide, CO 2 (g) and liquid water H 2 O (l): Read the rest of this entry