We explain what acetic acid is and the formula of this substance. In addition, its physical, chemical properties and its different uses.
What is acetic acid?
Acetic acid, also called methylcarboxylic acid or ethanoic acid, is an organic substance present in the vinegar composition , being responsible for its typical sour smell and taste.
We speak of a weak acid, a frequent result of various fermentation processes , such as those that take place in wine (when it is vinegar) or in certain fruits. It is ordinarily used in cooking, as a vegetable cleaner or salad dressing (such as vinegar, that is, diluted with water in 3 to 5% solute). However, in pure proportions it involves different risks to life in general.
In fact, the origin of the vinegar is intimately linked to the wine development in ancient times, since the boots or barrels of wine that were sour were removed for different use, saying that “the wine had been chopped.” This is due to the activity of the Mycoderma aceti bacteria and requires the presence of oxygen.
Acetic Acid Formula
Acetic acid responds to the chemical formula C2H4O2, being its semi-developed formula CH3COOH.
Seen this way, it is nothing more than a methyl molecule (CH3) with a carboxyl group (-COOH) attached to the carbon atom by single bond.
Physical properties of acetic acid
The appearance of acetic acid is crystalline, at least when it is found as its acetate ion (a salt or ester of the acid). It has a melting point of 16.6 ° C and a boiling point of 117.9 ° C, thanks to which it is possible to separate it from water by distillation . It also has a density of 1049 kg / m3 and a moderate acidity of 4.8.
It is a flammable and corrosive material at the same time , which makes its handling delicate, as it is capable of severely irritating the skin, eyes, and digestive tract (if swallowed) or respiratory (by inhalation).
Chemical properties of acetic acid
Acetic acid belongs to carboxylic acids (characterized by the presence of a functional carboxyl chemical group: -COOH), and is usually located in the classifications between formic or methanoic acid (which has a single carbon atom) and acid propanoic (which already has a chain of carbon atoms).
It is a weak acid, common as a biological metabolite and as a substrate for acetyltransferase enzymes. It is usually obtained by three different methods: carbonylation of methanol (CH3OH + CO → CH3COOH), oxidation of acetaldehyde (2CH3CHO + O2 → 2CH3COOH), oxidative fermentation (C2H5OH + O2 → CH3COOH + H2O) or anaerobic fermentation (C6H12O6 → 3CH3COOH ).
Applications and uses
Acetic acid has numerous applications in the human industry, such as:
- Control of wax moths (galleriosis) in beekeeping.
- Important component (in salts or esters) for the manufacture of nylon , rayon, cellophane and other films.
- Component of fixing substances in the preservation of organic tissues in the laboratory.
- It is part of the chemicals used in photographic development.
- Medical dye to reveal Human Papillomavirus (HPV) lesions.
- General purpose cleaner and stain remover component.
- Culinary uses as vinegar.