Oxalic acid is found in tomatoes, lactic acid in curd and acetic acid is found in vinegar.
Natural source of acetic acid – Vinegar
Natural source of oxalic acid – Tomatoes
Natural source of lactic acid – Curd
Any alcoholic solution can oxidise and produce a solution containing acetic acid, which is vinegar.
Acetic acid or ethanoic acid with chemical formula CH3COOH is a highly recognised organic compound that gives vinegar its sour taste and pungent odour. It is an example for one of the simplest carboxylic acids.