Stoichiometry of Chemical Reactions


actual yield

amount of product from a reaction determined experimentally

empirical formula

formula indicating the ratios of elements found in a compound in the lowest whole number possible

excess reactant

reactant that is not completely used up in a reaction

limiting reactant

reactant that is completely used up in a reaction, which determines the amount of product that can form

molar mass

mass of one mole of the atoms, molecules, or formula units that make up a substance


amount of a substance that contains as many particles as 12 grams of pure carbon-12, equal to 6.023×10236.023\times10^{23} (Avogadro's number) particles

mole ratio

ratio between the number of moles of any two substances in a chemical reaction.

molecular formula

formula indicating the number of atoms of each type of element in a molecule

percent yield

actual yield divided by theoretical yield, multiplied by 100 percent

standard molar volume

volume occupied by one mole of an ideal gas at STP (standard temperature and pressure), equal to 22.4 L

theoretical yield

amount of product predicted from a reaction using mole ratios from the balanced equation