Chemistry: Moles, Masses, and Formulas Vocabulary

Vocabulary flashcards covering core stoichiometric concepts, measurements, gas conditions, and chemical formula definitions.

anhydride

A compound that contains no water

atomic mass

The mass of an atom's protons and neutrons expressed in atomic mass units (amu) on the periodic table; on the periodic table, calculated as a weighted average that reflects isotope abundance

atomic mass unit (amu)

A mass unit equal to $1.66 \times 10^{-24}\,\text{g}$ or $1.661 \times 10^{-27}\,\text{kg}$

Avogadro's number

The number of atoms contained in one mole, $6.02 \times 10^{23}$

empirical formula

The simplest ratio of atoms in a substance

formula mass

The sum of the atomic masses of all atoms in a chemical formula expressed in atomic mass units (amu); also known as molecular mass for covalent substances

molecular mass

The formula mass of a covalent compound

hydrate

A compound that has water attached to its structure

molar mass

The mass of one mole of a given substance, expressed in grams per mole ($\text{g/mol}$)

molecular formula

The exact number and types of atoms in a molecule

molecular weight

The mass in grams of one mole of an element or compound - identical to formula mass and molecular mass

standard temperature and pressure (STP)

Conditions of one atmosphere of pressure and $0\,^{\circ}\text{C}$

standard molar volume

The amount of space taken up by 1 mole of any gas at standard temperature ($0\,^{\circ}\text{C}$) and pressure ($101.325\,\text{kPa}$); equal to $22.4\,\text{L}$