Picric acid: a brief description of the substance

Picric acid is a complex chemical that is a nitro derivative of phenol. By the way, this connection in science is known as "trinitrophenol". The substance itself, as well as its salts, are used as explosives.

Picric acid: formula and physical properties

The formula of trinitrophenol is as follows:

C6H2 (NO2) 3OH

In its pure form, picric acid is a solid that consists of lamellar crystals. Such crystals can be either colorless or have a slight yellowish tinge. The melting point of this substance is + 122.5 degrees Celsius.

The taste of trinitrophenol is very bitter, and its dust strongly irritates the nasal passages. Prolonged inhalation of the substance is dangerous for the human body, as it leads to poisoning, kidney damage and the appearance of skin diseases. It is undesirable to contact the substance with mucous membranes. For example, the conjunctiva of the eyes after getting on it the dust of picric acid acquires a yellowish tinge.

Picric acid: chemical properties and basic characteristics

Trinitrophenol is poorly soluble in water, although its solubility increases with increasing temperature. However, the ideal solvent for this substance is benzene, as well as methanol, chloroform and acetone.

Picric acid is also capable of forming so-called eutectic mixtures. The fact is that the high melting point creates certain technological difficulties in the equipping of ammunition. And when creating a mixture with nitronaphthalene or trinitrocresol, this indicator can be partially reduced.

It is also worth noting that trinitrophenol is a fairly strong acid, which quickly and actively enters the exchange reaction. As a result of interaction with metals salts are formed - the so-called picrates. The most commonly used salts are lead, sodium, iron and calcium. Interestingly, picric acid salts are more sensitive, which requires extra caution in the manufacture of ammunition.

Picric acid and explosive devices

In history, it was trinitrophenol that became the first effective explosive. Explosive properties of acid and its salts were discovered around the end of the eighteenth century, but it was actively used during military operations only in the 30s of the 19th century.

The use of trinitrophenol gave a new impetus to the development of military equipment. The fact is that picrates and picric acid itself had significantly greater shock-destructive properties than the powder used in those times.

The peak of its popularity such explosives reached during the Second World War. To date, this technology is practically not used.

How is trinitrophenol obtained ?

Picric acid can be obtained during the direct nitration reaction of phenol using high concentration nitric acid. But before thinking about where to buy nitric acid, it is worth noting that the process of producing picrin or picrates is very dangerous. History knows a lot of tragic events connected with it.

Use of picric acid

In fact, trinitrophenol is used not only to create explosives. This connection has become widespread in other areas of industry. For example, picrin is an intermediate product in the production of certain dyes.

The substance has received recognition in the medical field, where it is sometimes used as an antiseptic.

In the production of metals, picric acid is used as an etchant. And in the chemical industry, it is used as a catalyst during polymerization reactions. It also produces pigments for staining specimens in histology or for marking laboratory animals.