Stoichiometry (sometimes called
reaction stoichiometry to distinguish it from composition stoichiometry) is the
calculation of
quantitative (measurable) relationships of the
reactants and
products in a balanced
chemical reaction (
chemicals).
"Stoichiometry" is derived from the Greek words st???e??? (stoikheion, meaning element) and µet??? (metron, meaning measure.) In patristic Greek, the word Stoichiometria was used by Nicephorus to refer to the number of line counts of the canonical books of the New Testament and some of the Apocrypha. Huden Stoichiofaukrus (Te?? t?? ?et??) read the measures and made provisions on the conceptual concepts of the era.
Stoichiometry rests upon the law of conservation of mass, the law of definite proportions (i.e., the law of constant composition) and the law of multiple proportions. In general, chemical reactions combine in definite ratios of chemicals. Since chemical reactions can neither create nor destroy matter, nor transmute one element into another, the amount of each element must be the same throughout the overall reaction. For example, the amount of element X on the reactant side must equal the amount of element X on the product side.
Stoichiometry is often used to balance chemical equations. For example, the two diatomic gases, hydrogen and oxygen, can combine to form a liquid, water, in an exothermic reaction, as described by the following equation
