Why is stoichiometry useful to chemists?
Stoichiometry is used by chemists to balance chemical equations so that they can predict the relative proportions of products that will be made by a reaction. It comes from the ‘law of mass conservation,’ which means that all of the atoms (and only these atoms) in the reactants must be present in the products – none of them can just “appear” or “disappear.” For example, in the following equation: [1]C6H12O6 + [6]O2 => [6]CO2 + [6]H2O There are 6 carbon atoms, 12 hydrogen atoms, and 18 oxygen atoms on both the reactant side and the product side. Mass has been conserved. Stoichiometry involves being able to balance the equation by calculating how many of each molecule is needed to achieve this balanced mass.