• General Molecular formula of Saturated aliphatic monocarboxylic acids is CnH2n+1−COOH

  • Most of the aliphatic mono carboxylic acid obtained by the hydrolysis of natural fats hence they are also known are fatty acids.

  • Acetic acid ((CH3COOH)) is from vinegar (Latin: acetum means Vinegar). The chief constituent of vinegar is Acetic acid.

  • Carboxylic acids with two or more carboxyl groups attached are called dicarborxylic acids, tricarboxylic acids, etc. 

  • Carboxylic acids are derivatives of hydrocarbons in which one or more of the hydrogen atoms in the hydrocarbon have been replaced by a carboxyl group.


Carbon atoms

Common name

IUPAC name

Chemical formula

Common location or use


Formic acid

Methanoic acid


Insect stings


Acetic acid

Ethanoic acid




Propionic acid

Propanoic acid


Preservative for stored grains


Butyric acid

Butanoic acid


Rancid butter


Valeric acid

Pentanoic acid




Physical Properties –                                                                                                                                                                                   

  • At ordinary temperature, acetic acid is a colourless liquid with pungent odoured, corrosive liquid.

  • It is miscible with water, alcohol, and ether in all propotions.                                                                

  • It Boils at 391 K. The high Boiling point of acetic acid in comparison to alkanes.  

  • The higher acids are wax like solids and odourless due to their low volatility.

  • Carboxylic acids are also soluble in less polar organic solvents like benzene, ether, alcohol, chloroform etc.

Chemical Properties –

  • Electron with drawing group on C6H5 of aromatic carboxylic acid increases acidity where as, electron donating groups decrease acidity.

  • Electron with drawing groups increase the acidity of carboxylic acids by stabilising the carboxylate ion, the conjugate base through delocalisation of negative charge by inductive effect or resonance effects.

  • Carboxylic acids dissociate in water to give resonance stabilized carboxylate anions. The strength of an acid is given by its pKa value pKa=-logKa where Ka=acid dissociation constant

  • Lesser the pKa<1 value, stronger the acid

  • Increase in the number of Cl atoms at α - position (-I effect) increases the acidic strength and pKa value


Uses of Carboxylic Acid-

  • It is a good solvent.

  • In the preparation of acetates, acetones ,acetic anhydride.

  • In the prepararation perfumes, dyes, drugs

  • For curing meat and fish