Ferric chloride

The middle salt of iron chloride, whose formula is FeCl3, is a compound of ferric iron with hydrochloric acid. This substance is a plate (leaf) of a black-brown hue, which overflow and flicker under light. There are the same leaves of purple or greenish shade, which have a metallic luster.

This compound has a strong hygroscopicity, it is converted directly into air under normal conditions into a hydrate, the formula of which is FeCl3 • 6H2O. These crystals of yellow or yellow-brown hue are perfectly soluble in water - at the twenty-degree temperature of the solution in 100 grams of water, 91.9 g of anhydrous ferric chloride salt is completely dissolved.

The melting point of the substance is 309 ° C. In the chemical industry, it is usually produced in the form of anhydrous salt or in the form of a six-molecular crystalline hydrate. In industry, ferric chloride is used for the production of pure polystyrene, in the production of various varnishes. In all such technologies, the reaction takes place with the participation of phenol or the cresol ether of ethyl, which regulate the course of the reaction. As a rule, iron chloride is volatile and evaporates together with water vapor. When stored in a humid environment, the substance spreads out. This phenomenon can be observed even at 100 ° C, with a further increase in temperature and reaching a temperature of 317 ° C, iron chloride III begins to boil and volatilize with subsequent decomposition. Salt, prepared in this way, immediately crystallizes from the gas stage and settles on the vessel. The precipitate is so stable that it is not even washed off with carbon tetrachloride, which also condenses on the walls of the vessel.

Iron trichloride can be obtained in a fairly simple experiment. To do this, it is necessary to influence the sawdust of iron with chlorine, which is in the gaseous state. As a result of this reaction, a ferric iron salt will be obtained. This reaction differs from the reaction in which the active substance is hydrochloric acid.

In addition to this method, ferric chloride can be obtained as a result of an oxidation reaction in which chlorine and iron dichloride-2FeCl2 participate. More interesting from the point of view of application is the process for producing ferric trichloride by oxidation with sulfur (IV) oxide.

In the vapor form, iron trichloride has a structure that is almost identical to that of aluminum chloride, in the course of such a reaction, the separation of FeCl3 molecules begins when the temperature reaches a value of 500 ° C.

This substance is widely used as a coagulant in various technologies of water purification. In the chemical industry, it is used as a catalyst in the synthesis reactions of organic compounds. Widely used in textile production.

When heated, iron chloride, upon reaching the melting point and normal atmospheric pressure, decomposes into dichloride and chlorine molecules. Being a fairly strong Lewis acid, trichloride is able to participate in reactions with other chlorides. As a result of such reactions, various tetrachloro- ferric acid salts are obtained, and when it is heated with iron (III) oxide to 350 ° C, iron oxochloride is obtained.

As a rule, the salts of iron trichloride are weak oxidants, although there are exceptions. For example, it oxidizes copper copper quite easily. As a result of this reaction, soluble chloride CuCl and CuCl2 are obtained.

Iron trichloride is used as an etching agent in the manufacture of printed circuit boards in radio engineering and zincography. As a mordant, it is indispensable in textile production. In industrial volumes, trichloride iron is used in water purification technologies.

This compound is toxic, promotes corrosive processes. Avoid vaporization of the boiling of iron trichloride in the lungs.