Molecules, Compounds, and Chemical Equations

Vocabulary flashcards covering chemical formulas, bonds, nomenclature, acids, bases, electrolytes, molar mass, and chemical equations.

Chemical Formula

A notation indicating the elements present in a compound and the relative number of atoms or ions of each element.

Empirical Formula

A chemical formula that gives the relative, simplest whole-number ratio of atoms of each element in a compound.

Molecular Formula

A chemical formula that gives the actual number of atoms of each element in a molecule of a compound.

Structural Formula

A formula that uses lines to represent covalent bonds and shows how atoms in a molecule are connected or bonded to each other.

Ionic Bond

A chemical bond occurring between metals and nonmetals involving the transfer of electrons from one atom to another.

Covalent Bond

A chemical bond occurring between two or more nonmetals involving the sharing of electrons between atoms.

Basic Unit of a Molecular Compound

A discrete molecule composed of constituent nonmetal atoms.

Basic Unit of an Ionic Compound

A formula unit, which is the smallest, electrically neutral collection of ions in an ionic lattice.

Polyatomic Ion

A charged particle composed of two or more atoms held together by covalent bonds that remains intact during chemical reactions.

Oxyanion

A polyatomic anion containing oxygen combined with another element.

Arrhenius Acid

A substance that produces $H^+$ (or $H_3O^+$) ions in aqueous solution.

Arrhenius Base

A substance that produces $OH^-$ ions in aqueous solution.

Binary Acid

An acid containing hydrogen and only one other nonmetal element.

Oxyacid

An acid composed of hydrogen and an oxyanion.

Hydrate

An ionic compound that contains a specific number of water molecules associated with each formula unit.

Water of Hydration

Water molecules associated with a hydrate compound that can be removed by heating the substance.

Electrolyte Solution

An aqueous solution of a substance that conducts electricity due to the presence of dissolved ions.

Strong Electrolyte

A substance that dissociates completely ($100\%$) into ions when dissolved in water, forming a strongly conductive solution.

Weak Electrolyte

A substance that partially dissociates (typically $\sim 1\%$) into ions in aqueous solution, resulting in weak electrical conductivity.

Non-electrolyte

A compound that dissolves in water as intact molecular units without producing ions, resulting in a solution that does not conduct electricity.

Molecular Mass

The sum of the atomic masses of all atoms in a molecule, expressed in $\text{amu}$ or $g\,mol^{-1}$.

Chemical Equation

A symbolic shorthand representation of a chemical reaction displaying the formulas and physical states of reactants and products.