The stoichiometric coefficients of starting materials are often construed as the ideal proportions of starting materials, in the sense of not providing more initial concentration than needed to obtain, in the idealized case, a certain yield of a target product.
The purpose of this note is to formalize the concept of reaction-mechanism stoichiometry by relating the concept explicitly to ideal yield. The current, semi-formal notion of mechanism stoichiometry, as described by Corio [1989], has an ambiguity due to an uncertain, somewhat arbitrary decision of which mechanism species to regard as intermediates. This ambiguity makes the concept of stoichiometry less valuable for the discussion of ideal mechanism yields. We shall illustrate by example how our formalization in terms of linear programming removes this ambiguity, while gaining a clearer understanding of the relation between stoichiometry and ideal yield.