Foundations of Chemistry — 60 Terms Defined

Extensive Property Foundations of Chemistry Various A property whose value is directly proportional to the quantity of matter in the sample.

Filtration Foundations of Chemistry Dimensionless A separation technique that removes suspended solid particles from a fluid by passing the mixture through a porous medium.

Formula Unit Foundations of Chemistry Dimensionless The simplest whole-number ratio of ions represented in the empirical formula of an ionic or network compound.

Fractional Distillation Foundations of Chemistry Dimensionless A distillation carried out through a packed or plated column that repeatedly vaporises and condenses the mixture to separate liquids with close boiling points.

Heterogeneous Mixture Foundations of Chemistry Dimensionless A mixture in which the components remain physically distinct, so composition varies from one region of the sample to another.

Homogeneous Mixture Foundations of Chemistry Dimensionless A mixture whose composition and properties are uniform throughout, with no visible boundary between the components.

Hydrate Foundations of Chemistry Dimensionless A crystalline compound in which a definite number of water molecules is incorporated into the lattice. MX·nH₂O

Intensive Property Foundations of Chemistry Various A property whose value is independent of the amount of substance present.

Ion Foundations of Chemistry C (charge) An atom or group of atoms carrying a net electrical charge because its electron count differs from its proton count.

IUPAC Nomenclature Foundations of Chemistry Dimensionless The systematic naming rules issued by the International Union of Pure and Applied Chemistry that assign each substance one unambiguous name.

Law of Conservation of Mass Foundations of Chemistry kg The principle that the total mass of the substances in a closed system is unchanged by any chemical reaction. Σ m(reactants) = Σ m(products)

Law of Definite Proportions Foundations of Chemistry Dimensionless The principle that a given chemical compound always contains its constituent elements in the same fixed mass ratio.

Law of Multiple Proportions Foundations of Chemistry Dimensionless The principle that when two elements form more than one compound, the masses of one element combining with a fixed mass of the other are in small whole-number ratios.

Matter Foundations of Chemistry kg Anything that occupies space and possesses rest mass, existing in the solid, liquid, gas or plasma state.

Mixture Foundations of Chemistry Dimensionless A physical combination of two or more substances that keep their own chemical identities and can be present in any proportion.

Molar Mass Foundations of Chemistry g/mol The mass of one mole of a substance, numerically equal to its relative atomic or molecular mass expressed in grams. M = m / n

Molar Volume Foundations of Chemistry L/mol The volume occupied by one mole of a substance under stated conditions of temperature and pressure. V_m = V / n = RT / p

Mole Foundations of Chemistry mol The SI base unit for amount of substance, containing exactly 6.02214076 × 10²³ elementary entities. n = m / M

Molecular Formula Foundations of Chemistry Dimensionless The formula stating the actual number of atoms of each element present in one molecule of a compound. molecular formula = n × empirical formula

Molecular Mass Foundations of Chemistry Dimensionless The sum of the relative atomic masses of all atoms shown in a molecular formula. M_r = Σ A_r (all atoms)

Molecule Foundations of Chemistry Dimensionless An electrically neutral group of two or more atoms held together by covalent bonds, acting as the smallest unit of a covalent substance.

Percentage Composition Foundations of Chemistry Dimensionless The proportion by mass of each element in a compound, expressed as a percentage of the total mass. % element = (n × A_r / M_r) × 100

Physical Change Foundations of Chemistry Dimensionless A change that alters the form or state of a substance while leaving its chemical composition intact.

Physical Property Foundations of Chemistry Various A characteristic of a substance that can be observed or measured without altering its chemical identity.