Acetic acid

Acetic Acid

Acetic acid in its pure form.

Acetic acid (systematically named ethanoic acid) is a colorless liquid organic compound with the chemical formula CH_COOH. It is the main component of vinegar, apart from water, and has a distinctive sour taste and pungent smell.

Structure and Properties

Ball-and-stick model of acetic acid.

Acetic acid is a simple carboxylic acid consisting of a methyl group attached to a carboxyl group. Its molecular formula is C_H_O_, and its structural formula is CH_COOH. The molecule is polar, and it can form hydrogen bonds with water, making it miscible with water in all proportions.

Chemical Properties

Acetic acid is a weak acid, meaning it only partially dissociates in solution. The equilibrium constant for its dissociation in water is 1.8 _ 10__. The reaction can be represented as:

Deprotonation of acetic acid.

CH_COOH _ CH_COO_ + H_

Acetic acid can react with alcohols to form esters, a process known as esterification. It can also undergo oxidation to form carbon dioxide and water.

Production

Acetic acid is produced both synthetically and by bacterial fermentation. The most common synthetic method is the carbonylation of methanol, which involves the reaction of methanol with carbon monoxide in the presence of a catalyst.

Methanol carbonylation process.

Uses

Acetic acid is widely used in the production of polyvinyl acetate for wood glue, as well as synthetic fibers and fabrics. It is also used as a food additive and condiment, known as vinegar.

Biological Role

Acetic acid is an important metabolic intermediate. It is produced in the body during the breakdown of carbohydrates and fats and is a precursor to the biosynthesis of fatty acids.

History

An acetic acid production plant from 1884.

The use of acetic acid dates back to antiquity, where it was used in the form of vinegar. The first synthetic production of acetic acid was achieved in the 19th century.

Related Pages

• Vinegar
• Carboxylic acid
• Esterification
• Methanol

Gallery

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  Space-filling model of acetic acid.
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  Hydrogen bonding in acetic acid.