Reaction Stoichiometry

When reactants combine to form products in a chemical reaction they do so in a very precise way. For example in the reaction 2H2 + O2 --> 2H2O, exactly two hydrogen molecules react with exactly one oxygen molecule to form exactly 2 water molecules. This information, in combination with the principle of conservation of mass should allow us to accurately calculate precisely the amounts for reactants consumed as well as the amount of products generated in a chemical reaction. Calculations of this kind are known as "stoichiometric" calculations. There are three steps to successfully do stoichiometric calculations:

These points are covered successively in these web pages.