The four simplest carboxylic acids are methanoic acid, ethanoic acid, propanoic acid and butanoic acid.

 

Methanoic acid

Displayed formula:Image result for methanoic acid

Molecular formula: CH₂O₂

Structural formula: HCOOH

 

Ethanoic acid

Displayed formula:

Molecular formula: C₂H₄O₂

Structural formula: CH₃COOH

 

Propanoic acid

Displayed formula:Image result for propanoic acid

Molecular formula: C₃H₆O₂

Structural formula: CH₃CH₂COOH

 

Butanoic acid

Displayed formula:Image result for butanoic acid

Molecular formula: C₄H₈O₂

Structural formula: CH₃CH₂CH₂COOH