Chemical reactions

Abstract

In chemical reactions the additive constants in the internal energies and entropies of the constituents play a significant role. To be sure, it is not the constants themselves that matter but certain combinations, which we may call the heat of reaction and the entropy of reaction. These values can be determined experimentally and have been tabulated.

The balance of the heat of reaction and the entropy of reaction goes a long way in determining whether a reaction can proceed and in which direction it proceeds. We give some examples: Dissociation of oxygen, ammonia synthesis and photosynthesis of glucose. The latter appears to be impossible, if we did not know better.