Many carboxylic acids occur naturally.
Carboxylic acids are compounds whose molecules contain the functional group. Carboxylic acids are formed when primary alcohols or aldehydes are oxidised. They are also formed by hydrolysis of esters, many of which occur naturally. The physical properties are typical of hydrogen bonded substances, the lower acids being liquids at room temperature readily soluble in water. The important derivatives are acyl chlorides, esters and amides.