Formic acid

Formic acid (E 236, methanic acid) among the monoacids (saturated) is in the first place. Under normal conditions, the substance is a colorless liquid. Chemical formula of formic acid HCOOH.

Along with its acid characteristics, it also shows the qualities of aldehydes. This is due to the structure of substance E236.

In nature, the substance is found in the nettles, needles, fruits, caustic bees and secretions and in ants. Formic acid was first discovered and described in the 17th century. The substance got its name, because it was found in ants.

Typically, the component is used as an antibacterial and preserving agent in the preparation of feed. The chemical properties of formic acid slow the decay and decay processes. That is why silage and hay treated with this substance last longer. The substance is also used in medicine. In dyeing wool (mordant), as a bleaching agent for tanning of the skin, when fighting bees with parasites, formic acid is also used as a solvent in some reactions.

The chemical properties of the substance manifest themselves depending on the concentration. According to the EU classification, with a quantitative composition of up to 10%, it acts irritatingly, more than 10% is corrosive.

100% formic acid (liquid) in contact with skin provokes very severe burns. The occurrence of even a small amount of it in such a concentration on the cover causes severe pain. The affected area begins to whiten first, as if covered with hoarfrost, then becomes like wax. Around the burned area, a red rim is formed. The acid is able to quickly penetrate through the fatty skin layer, so it is necessary to immediately wash the affected area.

Concentrated vapors of the substance are capable of causing damage to the airways and eyes. Accidentally getting inside, even in a diluted form, methanic acid causes severe necrotic gastroenteritis.

The body quickly processes and removes the substance. However, along with this, E236 and formaldehydes, formed by methanol poisoning, provoke lesions in the optic nerve, which leads to blindness.

The salts of anthrax are called formates. Heating with concentrated sulfuric acid leads to the decomposition of E236 into H2O and CO, which is used to form carbon monoxide.

In industrial conditions, formic acid is obtained from sodium hydroxide and carbon monoxide.

The boiling point of the substance is 100.7, the freezing point is 8.25 degrees.

In room conditions, E236 decomposes into carbon monoxide and water. According to experimental evidence, methane acid is superior in strength to vinegar. However, due to the ability of the former to rapid decomposition, it is used as a solvent very rarely.

It is believed that E236 is a very hygroscopic substance. During the experiments, it was found that the preparation of anhydrous drug using dehydrating reagents is not possible.

It is inadmissible to contact formic acid with moist air.

E236 purity greater than 99% can be obtained from the aqueous solution by using a two-stage distillation using butyric acid. The first distillation removes the bulk of the water. The residue will contain about 77% of the substance. For its distillation, 3 to 6 times the amount of butyric acid in the form of an azeotropic mixture is used.

In the process of opening the container with E236, special care must be taken. When storing formic acid for a long period, a considerable pressure may form in the container.