3.2.3
Homologous Series
A family of compounds where successive members differ by \(-CH_2-\).
Key Characteristics
- Same Functional Group: Determines the chemical properties.
- Same General Formula: A mathematical formula for the entire series.
- Differ by \(-CH_2-\): Each successive member adds one methylene unit.
- Gradation in Physical Properties: Predictable trends in boiling point, density, etc.
- Similar Chemical Properties: They react in similar ways.
General Formulas
Alkanes
\(C_nH_{2n+2}\)
Alkenes
\(C_nH_{2n}\)
Alkynes
\(C_nH_{2n-2}\)
Alcohols
\(C_nH_{2n+1}OH\)
Carboxylic Acids
\(C_nH_{2n+1}COOH\)
Aldehydes
\(C_nH_{2n+1}CHO\)