Chemical Stoichiometry

Mole ratios, limiting reagents, and reaction yields

Stoichiometry uses the coefficients of a balanced chemical equation to calculate the amounts of reactants consumed and products formed. The mole ratio between any two substances equals the ratio of their coefficients. The limiting reagent is completely consumed first, determining the maximum product. Excess reagent remains after the reaction. Theoretical yield is the maximum possible product mass; actual yield is always less due to incomplete reactions or side reactions.