Homologous series

A homologous series is a family of compounds sharing a structural pattern, with successive members differing by a repeating unit. Members often show gradual changes in physical properties and similar chemical reactions.

Functional group: An atom or group of atoms that gives an organic molecule characteristic chemical reactions. Members often share a functional group, which explains their similar reactions.
Molecular mass: The sum of the atomic masses of the atoms in a molecule. Adding one repeating unit raises molecular mass by a predictable amount.
IUPAC nomenclature: The systematic rules for naming chemical substances established by the International Union of Pure and Applied Chemistry. Systematic names distinguish successive members while preserving their shared structural pattern.
Isomer: One of two or more compounds with the same molecular formula but different atom arrangements. Successive homologues differ in formula; isomers share a formula but differ in structure.
Alkane: A saturated hydrocarbon containing only carbon–carbon single bonds. Alkanes are a familiar homologous series whose members differ by CH₂.
Boiling point: The temperature at which a liquid's vapor pressure equals the surrounding pressure. Boiling points often rise along a series as molecular size and dispersion forces increase.
Organic chemistry: The study of carbon compounds, especially their structures, properties, reactions, and synthesis. Homologous series are a basic organizing framework for many families studied in this field.
Functional isomerism: A form of structural isomerism in which compounds share a molecular formula but have different functional groups. A homologous series holds its functional group constant, unlike this relationship.
Molecular formula: A notation showing the kinds and numbers of atoms in a molecule. A series often follows a general formula that captures its repeating composition.
London dispersion force: An intermolecular attraction caused by temporary fluctuations in electron distributions. Increasing molecular size commonly strengthens these forces and helps explain boiling-point trends.

Linked from 8 pages