acetic acid

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acetic acid

(əsē`tĭk), CH3CO2H, colorless liquid that has a characteristic pungent odor, boils at 118°C;, and is miscible with water in all proportions; it is a weak organic carboxylic acid (see carboxyl groupcarboxyl group
, in chemistry, functional group that consists of a carbon atom joined to an oxygen atom by a double bond and to a hydroxyl group, OH, by a single bond. Carboxylic acids are compounds whose molecules contain a carboxyl group that is joined to a hydrogen atom, an
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). Glacial acetic acid is concentrated, 99.5% pure acetic acid; it solidifies at about 17°C; to a crystalline mass resembling ice. Acetic acid is the major acid in vinegarvinegar,
sour liquid consisting mainly of acetic acid and water, produced by the action of bacteria on dilute solutions of ethyl alcohol derived from previous yeast fermentation.
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; as such, it is widely used as a food preservative and condiment. For industrial use concentrated acetic acid is prepared from the oxidation of acetaldehydeacetaldehyde
or ethanal
, CH3CHO, colorless liquid aldehyde, sometimes simply called aldehyde. It melts at −123°C;, boils at 20.8°C;, and is soluble in water and ethanol.
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. Acetic acid is also a product in the destructive distillation of wood. It reacts with other chemicals to form numerous compounds of commercial importance. These include cellulose acetate, used in making acetate rayon, nonflammable motion-picture film, lacquers, and plastics; various inorganic salts, e.g., lead, potassium, and copper acetates; and amyl, butyl, ethyl, methyl, and propyl acetatesacetate
, one of the most important forms of artificial cellulose-based fibers; the ester of acetic acid. The first patents for the production of fibers from cellulose acetate appeared at the beginning of the 20th cent.
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, which are used as solvents, chiefly in certain quick-drying lacquers and cements. Amyl acetate is sometimes called banana oil because it has a characteristic banana odor.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Acetic Acid


CH3COOH, a monobasic carboxylic acid of the aliphatic series. Acetic acid is a colorless liquid with a pungent odor and an acid taste. Anhydrous, or glacial, acetic acid has a melting point of 16.75°C, a boiling point of 118.1°C, and a density of 1.055 g/cm3 at 15°C. Acetic acid is miscible with water, alcohol, ether, benzene, and many other organic solvents. It is not soluble in carbon disulfide, but it readily dissolves many inorganic and organic substances, including sulfur, phosphorus, hydrogen halides, and cellulose acetate. Acetic acid is a weak acid, with a dissociation constant K = 1.75 × 10–5. It forms such typical derivatives of carboxylic acids as salts and esters, called acetates, an anhydride, an acid halide, amides, and anilides.

Acetic acid, in the form of vinegar, was the first acid known to man. It is widespread in nature both in free form and in the form of salts and esters, and it is formed during putrefaction and fermentation. There are four main industrial methods of preparing acetic acid: (1) oxidation of acetaldehyde by exposure to air or oxygen at 60°C in the presence of manganese acetate [(CH3COO)2Mn]; (2) pyrolysis of acetone with subsequent hydration of the resulting ketene

(3) oxidation of individual hydrocarbons, such as butane or benzine fractions; and (4) reaction of methanol with carbon monoxide. Another method, still of some importance, is the extraction of acetic acid from wood vinegar, one of the products obtained from the dry distillation of wood. The acetic acid in vinegar is obtained by the acetic fermentation of alcoholic liquids.

In industry, acetic acid, together with acetic anhydride and acetyl chloride, is used for introducing the acetyl radical (CH3CO—)—a process known as acetylation—in, for example, the preparation of the esters used as perfumes, solvents, and pharmaceuticals (acetylsalicylic acid, phenacetin). Salts of acetic acid are used in the preparation of pigments (acetates of lead and copper); other salts are used as catalysts (acetates of manganese, cobalt, zinc), and as mordants in dyeing (basic salts of acetic acid).

Acetic acid vapors irritate the mucosa and, in particular, the eyes; the permissible concentration of the vapors in the air is 0.005 milligram per liter. Concentrated (more than 30 percent) solutions of acetic acid cause burns upon contact with the skin.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

acetic acid

[ə′sēd·ik ′as·əd]
(organic chemistry)
A clear, colorless liquid or crystalline mass with a pungent odor, miscible with water or alcohol; crystallizes in deliquescent needles; a component of vinegar. Also known as ethanoic acid.
A mixture of the normal and acetic salts; used as a mordant in the dyeing of wool.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

acetic acid

a colourless pungent liquid, miscible with water, widely used in the manufacture of acetic anhydride, vinyl acetate, plastics, pharmaceuticals, dyes, etc. Formula: CH3COOH
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
Zorbax Eclipse XDB [C.sub.18] (Agilent, USA) was used as a stationary phase and 1% HOAc in a 20% aqueous MeOH was used as an initial mobile phase.
In our recent work [20], thermoplastic polyurethane/Si[O.sub.2] hybrids were produced using two types of catalyst systems, including acetic acid (HOAc) and HCl, to prepare sol particles starting from tetraethoxy silane (TEOS).
El residuo nuevamente fue utilizado para realizar una tercera extraccion con 20ml de solucion de clorhidrato de hidroxilamina (N[H.sub.2]OH x HCl) 0,04M en HOAc al 25% con agitacion continua durante 6h y manteniendolo a una temperatura constante de 96[grados]C; se filtro la muestra en membrana de 0,45[micro]m y la solucion se aforo a 100ml (fraccion reducible o unida a oxidos).
What are the benefits of attending the AOP's Hospital Optometrists Annual Conference (HOAC)?
The Cu fractions were sequentially determined using a 2.5 g soil sample with the following extractants: 25 mL of deionised water shake 2h, 120rpm (WS, water soluble); 25 mL of [MgCl.sub.2] 1.0 mol [L.sup.-1] pH 7.0 shake 2h, 120rpm (EXC, exchangeable); 25 mL of NaCaHEDTA 1%, N[H.sub.4]OAc 1 mol [L.sup.-1] pH = 8.3 shake 2h, 120rpm (SOR, weakly specifically adsorbed); 25 mL of Hydroquinone 0.2% in N[H.sub.4]OAc 1M a pH = 7.0 shake 2h, 120rpm (MnOX, easily reducible oxides bound); 25 mL of NaOAc 0.5 mol [L.sup.-1] - HOAc 0.5 mol [L.sup.-1] shake 2h, 120 rpm (CAR, carbonate bound); digestion: 5mL [H.sub.2][O.sub.2] 30%.
Esta recogida tambien en sus Obras completas, 6 vol., Ediciones HOAC, Madrid, 2010.
Two years later, HOAC was acquired by Diamond's current owners, a family well-established in the automotive business in Europe.