Acetic acid is a type of organic acid found in vinegar. It is the main component of vinegar, giving it its sour taste and pungent smell. ACETIC acid is also known as ethanoic acid and has the chemical formula C2H4O2. It is a weak acid, meaning that it does not completely dissociate in water, but still has some acidic properties. ACETIC acid is used in many food products, such as pickles, salad dressings, and sauces, as well as in cleaning products and pharmaceuticals.