August 26, 2025 | UR Gate
Oleic Acid (C18H34O2) Structure, Properties and Nomenclature
Discover Oleic Acid (C18H34O2), a monounsaturated omega-9 fatty acid. Learn its structure, key properties, IUPAC name, synonyms, and its roles in cardiovascular health, cell membranes, and as a component of fats and oils.
What is Oleic Acid (C18H34O2)?
Oleic acid is a monounsaturated omega-9 fatty acid, meaning it has an 18-carbon chain with a single cis-configuration double bond at the ninth carbon atom from the methyl end. It is one of the most common fatty acids found in nature, occurring in all animal and vegetable fats and oils, particularly in olive oil, from which it derives its name. Oleic acid is a liquid at room temperature and is considered a healthy fat, associated with reduced risk of cardiovascular disease by helping to lower LDL cholesterol levels and raise HDL cholesterol levels. It plays a role in cell membrane structure and function, and is used in various industrial applications, including the production of soaps and cosmetics.
Properties of Oleic Acid (C18H34O2)
| Property | Value |
|---|---|
| Molecular Formula | C₁₈H₃₄O₂ |
| Molecular Weight | 282.46 g/mol |
| Density | 0.893 g/cm³ (at 20°C) |
| Boiling Point | 286 °C (at 19 mmHg) |
| Melting Point | 13.4 °C |
| Hybridization | Carbons involved in the double bond are sp² hybridized; all other carbon atoms are sp³ hybridized. The carboxyl group carbon is sp² hybridized |
| Appearance | Colorless to pale yellow oily liquid |
| Solubility | Insoluble in water; soluble in organic solvents like ethanol, ether, and chloroform. |
Nomenclature of Oleic Acid
- Common name: Oleic acid
- IUPAC name: (9Z)-Octadec-9-enoic acid
Synonyms
- cis-9-Octadecenoic acid
- (Z)-9-Octadecenoic acid
- Oleine
- cis-9-Octadecenoyl chloride
- Acide oleique
