1. Carboxylic acids

2. Carboxylic acids Methanoic acid HCOOH Ethanoic acid CH3COOH
Propanoic acid C2H5COOH
Butanoic acid C3H7COOH

3. Methanoic acid HCOOH

4. Ethanoic acid CH3COOH

5. Propanoic acid C2H5COOH

6. Butanoic acid C3H7COOH

7. Physical properties
Physical state: Methanoic acid and ethanoic acid are liquids, while propanoic acid and butanoic acid are solids
Short chain carboxylic acids are soluble in water due to the polar COOH group
Carboxylic acids are soluble in non-polar solvents such as cyclohexane

8. Boiling points of carboxylic acids
Boiling points higher than the corresponding alcohols
This is because carboxylic acids form dimers, where two carboxylic acid molecules are held together by two hydrogen bonds
This is possible due to polarity in both the C=O and O-H bonds in each carboxylic acid molecule

9. Ethanoic acid dimer δ- δ+ δ- δ+ δ+ δ- δ+ δ-

10. Occurrence and uses
Methanoic acid is found in the sting of ants and nettles
Ethanoic acid is the principal acid in vinegar
Ethanoic acid is used in the manufacture of cellulose acetate
Propanoic acid, benzoic acid and their salts (e.g. sodium benzoate) are used as food preservatives