Bromine water is bromine diluted with water. It is customary to write it in the reaction equations through the formula Br2, although it is in solution in the form of a mixture of two acids - HBrO (hypobromic acid) and HBr (hydrobromic acid). This compound has a yellow-orange color and a rather low freezing point. It is a strong oxidizing agent, which is capable of oxidizing cations of such metals in an alkaline medium - Cr +3 , Mn +3 , Fe +2 , Co + 2 , Ni +3 . Adding Br 2 reduces the pH of the solution (pH), because bromine water contains free acids.
This is a chemically active substance that can interact with both inorganic and organic substances. Consider some chemical processes with this compound.
Bromine water discoloration serves as a qualitative response to all unsaturated hydrocarbons. To conduct such an experiment, a small amount of any alkene or alkyne must be mixed in a test tube with Br 2 . During this reaction, the addition of bromine atoms at the site of cleavage of a double or triple bond. The disappearance of the yellow-orange color in this interaction is evidence of the unsaturation of the hydrocarbon taken.
The chemical phenol-bromine water reaction is used to precipitate brominated compounds from solutions. If this interaction of substances is carried out in an anhydrous environment, the formation of tribromophenol will take a couple of days. Therefore, a small amount of H
2 O is added as a catalyst.
The bromine water in the laboratory is prepared as follows: 250 ml of distilled water is added to 1 ml of bromine, while stirring vigorously. The prepared solution is stored in a tightly closed container of dark glass. If the prepared Br 2 is stored in the light or in a bright bottle, then oxygen will be released due to the content of hypobromic acid. Work on the preparation of the reagent is carried out in a fume hood. Since bromine itself is toxic, and bromine water contains it, care must be taken when working with it.
It is necessary to take into account the fact that when Br
2 gets on the skin, severe itching appears, and with prolonged exposure, sores can occur. If the substance gets on the skin, it should be washed with plenty of water and then
with sodium carbonate. With a large wound surface or deep lesions of the epidermis, the skin is additionally lubricated with ointment, which includes NaHCO
3 .
Bromine water is widely used in chemical analysis and synthesis of organic preparations. So, it is used in the production of bromine-containing drugs. And here you need to be careful, because their prolonged use can lead to the disease - bromism. The main symptoms are apathy, lethargy, the appearance of a skin rash. For faster elimination of bromine ions from the body, a diet with a high salt content and plenty of drinking are followed. Still bromine water is used at intermediate stages of the production of flame retardants - substances that protect organic compounds from ignition. They impregnate fabrics, wood, building material.