Br 2 at normal temperature is a brownish-brown heavy liquid that forms poisonous vapors of a red-brown color with a pungent odor. Bromine is more soluble in water than chlorine. A saturated solution of Br 2 in water is called "bromine water".

Free I 2 at ambient temperature is a purple-tinted black-gray solid with a noticeable metallic luster. Iodine sublimes easily, has a peculiar smell (iodine vapors, like bromine, are very poisonous). The solubility of I 2 in water is the lowest among all halogens, but it is readily soluble in alcohol and other organic solvents.

Methods of obtaining

1. Bromine and iodine are extracted from seawater, underground brines and drilling waters, where they are contained in the form of Br - and I - anions. The release of free halogens is carried out using various oxidizing agents, most often gaseous chlorine is passed through:

2NaI + Cl 2 \u003d I 2 + 2NaCl

2NaBr + Cl 2 \u003d Br 2 + 2NaCI

2. Under laboratory conditions, to obtain Br 2 and I 2, the following reactions are used, for example:

2NaBr + MnO 2 + 2H 2 SO 4 \u003d Br 2 ↓ + MnSO 4 + Na 2 SO 4 + 2H 2 O

bNVg + 2H 2 SO 4 \u003d 3Br 2 ↓ + S ↓ + 4H 2 O

2HI + H 2 SO 4 \u003d I 2 ↓ + SO 2 + 2H 2 O

Chemical properties

By chemical properties bromine and iodine are similar to chlorine. The differences are mainly related to the conditions of the reactions. Let us note some important features of chemical reactions involving Br 2 and I 2.

Br 2 is a very strong oxidizing agent

Bromine is a liquid, unlike gaseous Cl 2, so the concentration of molecules in it is higher. This explains the stronger oxidizing effect of liquid bromine. For example, when iron and aluminum come into contact with it, it ignites even at normal temperatures.

Bromine water is a reagent for carrying out qualitative reactions

Bromine water has a yellow-brown color, which quickly disappears if dissolved Br 2 reacts with any substance. "Discoloration of bromine water" is a test for the presence of a number of inorganic and organic substances in a solution.

1. Detection of reducing agents in solutions

Gaseous SO 2 and H 2 S dissolved in water, as well as soluble sulfites and sulfides, discolor bromine water:

Br 2 + Na 2 SO 3 + H 2 O \u003d 2HBr + Na 2 SO 4

Br 2 + H 2 S \u003d 2HBr + S ↓

3Br 2 + Na 2 S + ЗН 2 O \u003d 6HBr + Na 2 SO 3

2. Detection of multiple carbon-carbon bonds

Qualitative reaction to unsaturated organic compounds - discoloration of bromine water:

R-CH \u003d CH-R "+ Br 2 → R-CHBr-CHBr-R"

3. Detection of phenol and aniline in organic solutions

Phenol and aniline easily interact with bromine water, and the reaction products do not dissolve in organic solvents, therefore they form precipitates:

С 6 Н 5 ОН + ЗBr 2 → С 6 Н 2 Br 3 ОН ↓ + ЗНВr

С 6 Н 5 NH 2 + ЗВr 2 → С 6 H 2 Br 3 NH 2 ↓ + ЗНВr

Iodine-starch reaction in qualitative analysis

Anions I are very easily oxidized by both strong and weak oxidants:

2I - -2e - → I 2

It is possible to detect the released I 2 even in small amounts with the help of a starch solution, which acquires a characteristic dirty blue color in the presence of I 2. Iodine-starch reaction is used in carrying out not only qualitative analysis, but also quantitative.

Reactions involving I 2 as a reducing agent

Iodine atoms have lower values \u200b\u200bof the electron and EO affinity energies compared to other halogens. On the other hand, the manifestation of some metallicity in iodine is explained by a significant decrease in the ionization energy, due to which its atoms donate electrons much more easily. In reactions with strong oxidants, iodine behaves as a reducing agent, for example:

I 2 + I0HNO 3 \u003d 2НIO 3 + 10NO 2 + 4Н 2 O

I 2 + 5H 2 O 2 \u003d 2HIO 3 + 4H 2 O

I 2 + 5Cl 2 + 6H 2 O \u003d 2HIO 3 + 10HCl

Hydrogen bromide and hydrogen iodide

HBr and HI are very similar in physical and chemical properties to HCl; therefore, attention should be paid only to practically important differences that must be taken into account when obtaining these substances.

Thermal instability HBr and HI

HBr and HI molecules are less stable than HCl; therefore, their synthesis from simple substances is difficult due to the reversibility of the reaction (especially in the case of HI).

H 2 + I 2 → 2HI

The Br - and I - anions are stronger reducing agents than the Cl - anions.

HCI is obtained by action of conc. H 2 SO 4 to chlorides (eg solid NaCl). Thus, hydrogen bromide and hydrogen iodide cannot be obtained, since they are oxidized with conc. H 2 SO 4 to free halogens:

2KBg + 2H 2 SO 4 \u003d Br 2 + SO 2 + 2H 2 O + K 2 SO 4

6KI + 4H 2 SO 4 \u003d 3I 2 + S + 4H 2 O + 3K 2 SO 4

Obtaining HBr and HI:

1) from bromides and iodides

It is necessary to displace HBr and HI from their salts with non-volatile non-oxidizing orthophosphoric acid

KBr + H 3 PO 4 \u003d HBr + KN 2 PO 4

2) hydrolysis of nonmetal halides

KI + H 3 PO 4 \u003d HI + KN 2 PO 4

3) reduction of free halogens in aqueous solutions

PBr 3 + ZN 2 O \u003d H 3 PO 3 + ZNVr

РI 3 + ЗН 2 O \u003d H 3 PO 3 + 3HI

Br 2 + SO 2 + 2H 2 O \u003d 2HBr + H 2 SO 4

l 2 + H 2 S \u003d 2HI + S ↓

4Br 2 + BaS + 4H 2 O \u003d 8HBr + BaSO 4

The history of the origin of bromine goes back to the distant 20s of the 19th century. During this period, two chemists, German Levich and French Balard, identified a new chemical element. The French chemist Balard assigned the primary name to his discovery "murid", which means brine.

This is due to the fact that during this period the chemist was engaged in a thorough study of the Mediterranean salt fields.

Bromine: characteristic of a trace element

Due to the presence of a characteristic, unpleasant, specific smell, the identified chemical element received a new name bromine. It is one of the main components of Mendeleev's periodic table of chemical elements. In this table, bromine is in the seventh group of the 4th period. Bromine is a chemical element with non-metallic properties, atomic number 35 and molecular weight about 80. It is designated by the chemical symbol Br.

Natural places of localization of a trace element

Bromine is a common ingredient found in almost every element environment... The highest concentration of this substance is found in sea and lake water. Depending on the geographic location of water bodies, bromine can have the following compounds: potassium bromide, sodium bromide or magnesium bromide. The maximum amount of this substance appears when the sea water evaporates. Bromine is also found in many plants and even in rocks. It should be noted that sea salt is a natural bromine-rich product.

With normal body functioning, the average bromine content is 300 mg. The main places of localization of this element:

• Thyroid.
• Liquid mobile connective tissue.
• Kidneys.
• Pituitary.
• Muscle.
• Bone.

Basic properties of bromine

This chemical element is characterized by a liquid form with a high density, a reddish-brown tint, and a pungent unpleasant odor. It is the only non-metal that retains its original form under room conditions.

Bromine and the products of its evaporation are toxic and poisonous substances, which, when in contact with the skin and mucous membranes, contribute to the occurrence of a burn. Therefore, given the properties of bromine, it is necessary to work with it in special conditions, using personal protective equipment.

Natural bromine is composed of two stable isotopes. Its molecule contains 2 atoms, which is why this element in chemistry is denoted by the formula Br2.

How much bromine does a person need per day?

The average healthy person needs a certain amount of bromine for the normal functioning of all body systems. Its norm is from 0.3 to 1 g. The exact amount is selected taking into account age, area of \u200b\u200bresidence, lifestyle and quality of food.

What foods contain bromine

Food is one of the main sources of bromine for humans. Among them it is worth highlighting:

• Various varieties of nuts.
• Legumes.
• Durum wheat pasta and flour products.
• Milk products.
• Kelp.
• Crushed barley.
• Whole wheat grains.
• Sea fish.

The negative effect of bromine on the body

Bromine in its pure form belongs to strong poisons, oral intake of which is unacceptable. Its vapors provoke a rapid accumulation of fluid in the lungs. It is because of these properties of bromine that it carries a great danger to the life of a person who suffers from allergies, asthma or various lung diseases.

It is also forbidden to take bromine during activities that require strong attention and concentration.

The main signs of excess bromine in the body

Excess allowable quantity bromine in the body can only be triggered by taking pharmaceutical drugs. Its excess carries a significant threat to the normal functioning of the body and life. That is why, when the first signs of an overdose appear, you should immediately seek qualified medical help to adjust the daily rate.

Typical symptoms:

• Rash on the skin.
• Development of inflammatory processes on the skin.
• Dysfunction of the digestive system.
• Weakness.
• Depressive state.
• Chronic bronchitis and rhinitis that are not caused by a cold.

Bromine deficiency

With an insufficient amount of bromine in the body, the following symptoms appear:

• Asomnia.
• Suspension of growth in childhood and adolescence.
• Decrease in the level of hemoglobin in the blood.
• The risk of spontaneous abortion during pregnancy.

Only a doctor is able to accurately determine the cause of the disease associated with a deficiency of bromine in the body based on the results of laboratory examinations. Self-treatment in this case is unacceptable.

Useful properties of bromine

In medical practice, bromine is used in the form of bromides. Depending on the pathologies, a certain type is assigned. The main focus of these drugs is sedation. That is why such drugs are included in the therapeutic course in the treatment of nervous disorders, sleep disorders, seizures, epilepsy. Normalize the functionality of the cardiovascular system and organs of the gastrointestinal tract.

Bromine antagonists

The main substances that slow down the process of assimilation of bromine include:

• Chlorine.
• Aluminum.
• Fluorine.

That is why bromine-containing drugs are taken exclusively as directed by a doctor.

Effects of bromine on erectile function

There is an opinion that bromine has a negative effect on male libido and potency. That is why it is added to the food of soldiers in the army, patients in psychiatric hospitals, and also prisoners in prisons. But scientists have proven that bromine simply has a calming effect on the entire body, while not inhibiting potency in any way.

It is also worth noting that under the influence of bromine, on the contrary, sexual functions are activated and the number of sperm and sperm contained in them significantly increases.

Where is bromine used in human life?

In human life, bromine is used not only as a medicinal product. It is also often used in other areas that provide modern human life. Bromine-based substances are used in the oil refining industry and in the manufacture of fuels, lubricants, photographs and chemical weapons.

Bromine is a simple substance, halogen, discovered at the beginning of the 19th century. Not the most common element on Earth, but widely dispersed: it can be found in the seas and oceans, in lakes and groundwater, in the earth's crust, atmosphere, in plants (legumes, algae). It does not occur in its pure form due to its high chemical activity. There are few bromine minerals and they have no industrial value. Bromine is extracted from sea water, bitter lakes, groundwater accompanying oil fields.

Properties

Heavy liquid, dark red. Only bromine and mercury of all simple substances are liquids under normal conditions. The smell is unpleasant, it was he who gave the name to the substance (from the Greek "bromos", meaning a bad smell). It dissolves poorly in water, although better than other halogens. Mixes up with organic solvents in any proportion.

The reactive element, a strong oxidizing agent, forms a fairly strong hydrobromic acid HBr. In addition, it forms a number of oxygen-containing acids. Reacts with halogens, non-metals, metals. Does not react with oxygen, nitrogen, platinum, tantalum. Forms bromides, easily attaches to organic compounds.

It is necessary to distinguish between bromine, as a chemical element, and the medicine "bromine", which is prescribed in the clinic as a sedative. Bromine is very toxic, and potassium bromide or sodium bromide is used for medical purposes, which enhance the inhibition processes in the central nervous system.

Bromine and its vapors are poisonous; when in contact with the skin, liquid bromine causes long-lasting chemical burns. It is allowed to work with the reagent only with the use of all protective equipment, including special clothing, gloves and a gas mask. Inhalation of bromine vapor is especially dangerous for people with respiratory diseases, as pulmonary edema may develop. In case of bromine poisoning, provide a person with fresh air or inhalation of oxygen and call a doctor. Warm milk, soda, soda-containing mineral water, coffee helps. Sodium thiosulfate solution serves as antidote and neutralizer for bromine spills. It can also be used to impregnate facial dressings to protect against vapor. For small spills, regular soda will work, but the reaction with bromine is exothermic, causing an increase in air temperature and intensifying fumes, so it is better to have sodium thiosulfate on hand.

Application

- In the chemical industry, bromine is used to produce organic and inorganic compounds, such as potassium and sodium bromide, hydrobromic acid, dibromoethane and many others.
- Bromine is in demand for producing high quality rubber.
- For analytical purposes, bromine, bromic water, potassium bromide, sodium bromide are used.
- Silver bromide is used as a light-sensitive material in photography.
- Almost half of the bromine produced is used to obtain 1,2 dibromoethane, which is included in the fuel as an antiknock additive, is used to protect wood from damage by insects, in organic synthesis.
- Bromine is widely used to obtain fire retardants - special additives and impregnations that impart fire-fighting properties to paints, plastics, wood, textile materials.
- Bromochloromethane is used to fill fire extinguishers.
- Bromine pentafluoride is used in rocket fuel.
- In agriculture, bromine compounds are used to control plant pests.
- Bromide solutions are used in oil production, at mining and processing plants.
- In medicine, KBr and NaBr solutions are included in sedatives, for example, in Corvalol.
- Bromine can be used as a disinfectant to replace chlorine in swimming pools, water treatment plants.

Potassium bromide, sodium bromide, hydrobromic acid, standard-titer potassium bromide are sold in our online store at competitive prices.

BROMINE (Latin - Bromum), Br, chemical element of group VII of short form (17th group of long form) of the periodical system; refers to halogens; atomic number 35, atomic mass 79.904. There are two stable nuclides in nature: 79 Br (50.56% by weight) and 81 Br (49.44%). Nuclear isomerism is characteristic of the artificially obtained 80 Br radionuclide.

History reference... Bromine was first isolated in 1826 by the French chemist A. J. Balard, acting with chlorine on an aqueous solution obtained after washing the ash of seaweed. The Latin name for the element comes from the Greek βρ? Μος - stench and is associated with the strong unpleasant smell of its vapors.

Prevalence in nature... The bromine content in the earth's crust is about 1.6-10 -4% by weight. Due to its high chemical activity, it does not occur in free form. Bromine in the form of an isomorphic admixture of sodium, potassium, magnesium and other bromides is part of natural chlorides (in sylvite and carnallite, the bromine content is up to 3%). Bromine's own minerals - bromargyrite AgBr and embolith Ag (Cl, Br) - are extremely rare. The source of bromine is sea water, brine from salt lakes, groundwater accompanying oil and various salt deposits.

Properties... The configuration of the outer electron shell of the bromine atom is 4s 2 4p 5; in compounds, bromine exhibits oxidation states -1, +1, +5, rarely +3 and +7; Pauling electronegativity 2.8; the atomic radius is 119 pm, the radii of the Br - and Br 5+ ions are 182 and 45 pm, respectively. In free form in all states of aggregation, it exists in the form of diatomic molecules Br 2. Dissociation of molecules into atoms begins to a noticeable extent at temperatures above 800 ° C.

Under normal conditions, bromine is a heavy (at 25 ° C density 3105.5 kg / m 3) dark brown liquid with a pungent odor; t PL -7.25 ° С, t bp 59.2 ° С. It is slightly soluble in water (at 20 ° C about 3.5% by weight of Br 2), a solution of bromine in water is bromine water. Bromine is readily soluble in many organic solvents. The standard electrode potential of the Br 2 / Br pair is +1.065 V in aqueous solution.

Bromine is characterized by high chemical activity; at room temperature, it actively reacts with the release of a large amount of heat with many metals and non-metals. In reactions with metals, salt-like substances are formed - bromides, in which bromine exhibits an oxidation state of -1 (for example, potassium bromide KBr, magnesium bromide MgBr 2, aluminum bromide AlBr 3). Bromine does not react with silver, lead and platinum; bromides of these metals are obtained indirectly. Most of the metal bromides are readily soluble in water, the pale yellow silver bromide AgBr is insoluble. Bromine reacts with non-metals at room temperature or when heated. For example, the interaction of bromine vapor with hydrogen when heated leads to the formation of hydrogen bromide HBr. Bromine does not directly interact with carbon, oxygen, nitrogen and noble gases. With many organic compounds, bromine enters into substitution reactions (for example, with benzene) or addition at multiple bonds (for example, with ethylene or acetylene). In terms of chemical activity, bromine is slightly inferior to chlorine, but superior to iodine. So, chlorine displaces bromine from solutions of its salts (for example, 2KBr + Cl 2 \u003d 2KCl + Br 2), but bromine is able to displace iodine (Br 2 + 2KI \u003d 2KBr + l 2). Compounds in which bromine exhibits an oxidation state of +5 are bromates. Thus, in the reactions of bromine with solutions of alkalis or alkali metal carbonates, a mixture of bromide and bromate is usually formed (for example, sodium bromide NaBr and sodium bromate NaBrO 3). When bromine interacts with alkalis in the cold, hypobromitones (for example, NaBrO) are formed - salts of the unstable hypobromous acid HBrO, which, when heated and at pH< 9 превращаются в броматы. Бром - сильный окислитель; в щелочной среде бром может окислить соединения хрома (III) до хрома (VI): 2К[Сr(ОН) 4 ] + 3Вr 2 + 8КОН = 2К 2 СrO 4 + 6КВr + 8Н 2 O.

Bromine is found in trace amounts in animal tissues (about 1 × 10 -4%) and plants (about 1-10 -4%). Bromide ions Br - enhance the processes of inhibition in the cerebral cortex, therefore an aqueous solution of potassium or sodium bromide is used as a sedative.

Receiving... Bromine is isolated from seawater, brine from salt lakes, potash production wastes, and by other means by oxidation of bromides with chlorine and subsequent stripping of Br 2 with steam or air. Vapors of Br 2 are separated from water and impurities by rectification, from a bromo-air mixture - by absorption of Br 2 with a solution of iron (II) bromide.

Application... Bromine is mainly used to obtain bromine-containing inorganic (NaBr, KBr, HBr, etc.) and organic (mainly mono- and dibromoethane, used as fuel additives, etc.) compounds widely used in photography of silver bromide AgBr, in the synthesis a number of organic dyes and medicines.

Bromine is toxic. Bromine vapors irritate mucous membranes, cause choking, spasms and upper respiratory tract, dizziness, etc.; liquid bromine causes skin burns, dermatitis.

Lit .: Ksenzenko V.I., Stasinevich D.S. Chemistry and technology of bromine, iodine and their compounds. M., 1979; Polyansky N.G. Analytical chemistry of bromine. M., 1980.

Bromine (lat. Bromum), Br, a chemical element of the VII group of Mendeleev's periodic system, refers to halogens; atomic number 35, atomic mass 79.904; red-brown liquid with a strong unpleasant odor. Bromine was discovered in 1826 by the French chemist A. Zh. Balard in the study of brines from Mediterranean salt fields; named from the Greek. bromos - stench. Natural bromine consists of 2 stable isotopes 79 Br (50.54%) and 81 Br (49.46%). Of the artificially obtained radioactive isotopes, Bromine is the most interesting 80 Br, on the example of which IV Kurchatov discovered the phenomenon of isomerism of atomic nuclei.

Distribution of bromine in nature. The Bromine content in the earth's crust (1.6 · 10 -4% by mass) is estimated at 10 15 -10 16 tons. In its main mass, Bromine is found in a dispersed state in igneous rocks, as well as in widespread halides. Bromine is a constant companion of chlorine. Bromide salts (NaBr, KBr, MgBr 2) are found in deposits of chloride salts (in table salt up to 0.03% Br, in potassium salts - sylvine and carnallite - up to 0.3% Br), as well as in seawater (0.065% Br), brine from salt lakes (up to 0.2% Br) and underground brines, usually associated with salt and oil fields (up to 0.1% Br). Due to the good solubility in water, bromide salts accumulate in the residual brines of sea and lake water bodies. Bromine migrates in the form of readily soluble compounds, very rarely forming solid mineral forms represented by bromyrite AgBr, embolith Ag (Cl, Br) and iodembolite Ag (Cl, Br, I). The formation of minerals occurs in oxidation zones of sulfide silver-bearing deposits that form in arid desert areas.

Physical properties of Bromine. At -7.2 ° C, liquid bromine solidifies, turning into red-brown needle-like crystals with a faint metallic luster. Bromine vapors are yellow-brown in color, bp 58.78 ° С. The density of liquid bromine (at 20 ° C) is 3.1 g / cm 3. Bromine is only slightly soluble in water, but better than other halogens (3.58 g of Bromine in 100 g of H 2 O at 20 ° C). Below 5.84 ° C, garnet-red crystals of Br 2 · 8H 2 O are precipitated from water. Bromine is especially well soluble in many organic solvents, which is used to extract it from aqueous solutions. Bromine in solid, liquid and gaseous state consists of 2-atomic molecules. A noticeable dissociation into atoms begins at a temperature of about 800 ° C; dissociation is observed under the action of light.

Chemical properties of Bromine. The configuration of the outer electrons of the bromine atom is 4s 2 4p 5. The bromine valence in the compounds is variable, the oxidation state is -1 (in bromides, for example KBr), +1 (in hypobromites, NaBrO), +3 (in bromites, NaBrO 2), +5 (in bromates, KBrO3) and +7 ( in perbromates, NaBrO 4). Chemically, bromine is very active, occupying a place between chlorine and iodine in terms of reactivity. The interaction of Bromine with sulfur, selenium, tellurium, phosphorus, arsenic and antimony is accompanied by strong heating, sometimes even the appearance of a flame. Bromine also reacts vigorously with some metals, such as potassium and aluminum. However, many metals react with anhydrous bromine with difficulty due to the formation on their surface of a protective film of bromide, insoluble in bromine. Of the metals, silver, lead, platinum and tantalum are the most resistant to the action of bromine, even at elevated temperatures and in the presence of moisture (gold, unlike platinum, reacts vigorously with bromine). Bromine does not directly combine with oxygen, nitrogen and carbon even at elevated temperatures. Bromine compounds with these elements are obtained indirectly. Such are the extremely fragile oxides Br 2 O, BrO 2 and Br 3 O 8 (the latter is obtained, for example, by the action of ozone on Bromine at 80 ° C). Bromine interacts directly with halogens, forming BrF 3, BrF 5, BrCl, IBr and others.

Bromine is a strong oxidizing agent. So, it oxidizes sulfites and thiosulfates in aqueous solutions to sulfates, nitrites to nitrates, ammonia to free nitrogen (3Br 2 + 8NH 3 \u003d N 2 + NH 4 Br). Bromine displaces iodine from its compounds, but itself is displaced by chlorine and fluorine. Free bromine is released from aqueous solutions of bromides also under the action of strong oxidants (KMnO 4, K 2 Cr 2 O 7) in an acidic medium. When dissolved in water, bromine partially reacts with it (Br 2 + H 2 O \u003d HBr + HBrO) with the formation of hydrobromic acid HBr and unstable hypobromous acid HBrO. A solution of bromine in water is called bromine water. When bromine dissolves in alkali solutions in the cold, bromide and hypobromite (2NaOH + Br 2 \u003d NaBr + NaBrO + H 2 O) are formed, and at elevated temperatures (about 100 ° C) bromide and bromate (6NaOH + 3Br 2 \u003d 5NaBr + NaBrO 3 + 3H 2 O). Of the reactions of Bromine with organic compounds, the most characteristic additions are at the C \u003d C double bond, as well as the replacement of hydrogen (usually under the action of catalysts or light).

Getting Bromine. The initial raw material for the production of Bromine is seawater, lake and underground brines and lye of potash production, containing Bromine in the form of bromide ion Br - (from 65 g / m 3 in seawater to 3-4 kg / m 3 and higher in potash lye production). Bromine is isolated with chlorine (2Br - + Cl 2 \u003d Br 2 + 2Cl -) and distilled off from the solution with water vapor or air. Steam stripping is carried out in columns made of granite, ceramics or other Bromine-resistant material. Heated brine is fed into the column from above, and chlorine and water vapor from the bottom. Bromine vapors leaving the column are condensed in ceramic coolers. Next, bromine is separated from water and purified from chlorine impurities by distillation. Stripping with air makes it possible to use brines with its low content to obtain Bromine, from which it is unprofitable to separate Bromine from the steam method as a result of a high steam consumption. Bromine is captured by chemical absorbers from the resulting bromine-air mixture. For this, solutions of iron bromide (2FeBr 2 + Br 2 \u003d 2FeBr 3) are used, which, in turn, is obtained by the reduction of FeBr 3 with iron shavings, as well as solutions of sodium hydroxides or carbonates or gaseous sulfur dioxide reacting with Bromine in the presence of water vapor with the formation of hydrobromic and sulfuric acids (Br 2 + SO 2 + 2H 2 O \u003d 2HBr + H 2 SO 4). Bromine is isolated from the obtained intermediates by the action of chlorine (from FeBr 3 and HBr) or acid (5NaBr + NaBrO 3 + 3 H 2 SO 4 \u003d 3Br 2 + 3Na 2 SO 4 + 3H 2 O). If necessary, intermediate products are processed into bromide compounds without emitting elemental bromine.

Inhalation of Bromine vapors with their content in the air of 1 mg / m 3 or more causes cough, runny nose, nosebleeds, dizziness, headache; at higher concentrations - suffocation, bronchitis, sometimes death. The maximum permissible concentration of Bromine vapor in the air is 2 mg / m 3. Liquid Bromine acts on the skin, causing poorly healing burns. Work with Bromine should be carried out in fume hoods. In case of poisoning with Bromine vapor, it is recommended to inhale ammonia, using for this purpose a highly diluted solution of it in water or ethyl alcohol. Sore throat caused by inhalation of Bromine vapor is treated with hot milk ingestion. Bromine on the skin is washed off with plenty of water or blown off with a strong stream of air. The burnt places are smeared with lanolin.

Application of Bromine. Bromine is widely used. It is a starting product for the preparation of a number of bromide salts and organic derivatives. Large amounts of bromine are consumed to obtain ethyl bromide and dibromoethane - components of ethyl liquid added to gasoline to increase their detonation resistance. Bromine compounds are used in photography, in the production of a number of dyes, methyl bromide and some other Bromine compounds are used as insecticides. Some organic bromine compounds are effective extinguishing agents. Bromine and bromine water are used in chemical analyzes to determine many substances. In medicine, sodium, potassium, ammonium bromides are used, as well as organic compounds of Bromine, which are used for neuroses, hysteria, irritability, insomnia, hypertension, epilepsy and chorea.

Bromine in the body. Bromine - constant component tissues of animals and plants. Terrestrial plants contain on average 7 · 10 -4% Bromine per wet substance, animals ~ 1 · 10 -4%. Bromine is found in various secrets (tears, saliva, sweat, milk, bile). In the blood of a healthy person, the Bromine content ranges from 0.11 to 2.00 mg%. With the help of radioactive bromine (82 Br), it was established that it is selectively absorbed by the thyroid gland, the medulla of the kidneys and the pituitary gland. Bromides introduced into the body of animals and humans increase the concentration of inhibition processes in the cerebral cortex, help normalize the state of the nervous system, which has suffered from overstrain of the inhibitory process. At the same time, lingering in the thyroid gland, Bromine enters into a competitive relationship with iodine, which affects the activity of the gland, and in this regard, the state of metabolism.