Chapter 3 - Stoichiometry

HCS Chemistry II - Chapter 3 - Stoichiometry - Vocabulary

chemical stoichiometry

the calculation of the quantities of material consumed and produced in chemical reactions

mass spectrometer

an instrument used to determine the relative masses of atoms by the deflection of their ions on a magnetic field (§ 3.2)

average atomic mass (also known as atomic weight)

the weighted average mass of the atoms in a naturally occurring element (§ 3.2)

mole (mol)

the number equal to the number of carbon atoms in exactly 12 grams of pure Carbon-12: Avogadro's number (§ 3.3)

Avogadro's number

equal to 6.022x10^23 units (§ 3.3)

molar mass (also called molecular weight)

the mass in grams of one mole of molecules or formula units of a substance (§ 3.4)

mass percent

the percent by mass of a component of a mixture or of a given element in a compound (§ 3.6)

empirical formula

the simplest whole-number ratio of atoms in a compound (§ 3.7)

molecular formula

the exact formula of a molecule, giving the types of atoms and the number of each type (§ 3.7)

chemical equation

a representation of a chemical reaction showing the relative numbers of reactant and product molecules (§ 3.8)

reactants

a starting substance in a chemical reaction

products

a substance resulting from a chemical reaction

mole ratio

the ratio of moles of one substance to moles of another substance in a balanced chemical equation (§ 3.10)

limiting reactant

the reactant that is completely consumed when a reaction is run to completion (§ 3.11)

theoretical yield

the maximum amount of a given product that can be formed when the limiting reactant is completely consumed (§ 3.11)

percent yield

the actual yield of a product as a percentage of the theoretical yield (§ 3.11)