Among all the chemical elements, there is a special series of non-metals - halogens.These atoms were named for their special properties that they exhibit in chemical interactions.These include:
- iodine;
- chlorine;
- bromine;
- fluorine.
chlorine and fluorine - a poisonous gases, having a strong oxidizing power.Iodine under normal conditions is a crystalline substance dark purple color with metallic luster pronounced.It shows the properties of the reducing agent.And the fourth looks like a halo?What properties the bromine compound formed by them and the characteristics as an element, and as a simple substance?Try to understand.
Brom: general characteristic element
as particles of the periodic system, bromine occupies the cell under the ordinal number 35. Accordingly, as part of its nucleus 35 protons and electron shell can hold the same number of electrons.The configuration of the outer layer: 4s2p5.
Located in the VII group, the main group, part of the halogens - special properties of groups of chemical elements.In total there are about 28 different species of atom isotope.The mass numbers range from 67 to 94. The strength and stability, as well as prevailing on the percentage of naturally know two:
- bromine 79 - 51% of it;
- bromine 81 - 49% of it.
average atomic mass of an element is equal to 79.904 units.The oxidation state of the bromine ranges from -1 to +7.Exhibits strong oxidizing properties, but inferior in these chlorine and fluorine, iodine excelling.
History of discovery
Open this element was later his colleagues in the subgroup.By the time it was already known about the chlorine and iodine.Who made this discovery?You can call the name just three, because it is so much the scientists were able to synthesize almost simultaneously a new element, it turned out later considered atom.These names:
- Antoine Jerome Balar.
- Carl Ruslan Levyha.
- Justus Liebig.
However, the official "father" is considered to Balar, since he not only got the first and described, but also to send a scientific conference of chemists a new substance, which is the unknown element.
Antoine Balar was researching the composition of sea salt.Drawing on her many chemical experiments, he one day passed through a solution of chlorine and saw that is formed for a yellow compound.Taking this as a reaction product of iodine and chlorine in the solution, it was further explore the resulting product.Subjecting the following treatments:
- worked ether;
- soaked in potassium hydroxide;
- handled pyrolusite;
- sustained in sulfuric acid.
As a result, he received a volatile brownish-red liquid with an unpleasant odor.This was bromine.Then he made a careful study of the physical and chemical characteristics of this substance.When it sent the report, he described the properties of bromine.A name that gave Balar element was murid, but it did not stick.
Today's common name of a bromine atom, which translated from Latin means "stinky", "stinking".This is fully confirmed by the properties of its simple substance.Year of opening element - 1825.
possible oxidation state bromine
these it is possible to name a few.After all, thanks to its electronic configuration, bromine can be both oxidizing and reducing properties, with a clear predominance of the first.Total There are five options:
- -1 - lower oxidation bromine;
- +1;
- +2;
- +3;
- +5;
- +7.
In nature, there are only those in which structure element in the negative sense.7 - maximum oxidation bromine.It shows it as part of bromine HBrO4 acid and its salts, bromates (NaBrO4).In general, this degree of oxidation of bromine is extremely rare, as well as two.But connection to -1;3 and 5 - very common and are important not only in the chemical industry, but also in medicine, engineering and other sectors of the economy.
Bromo as a simple substance
Under normal conditions the element in question is a diatomic molecule, however, is not gas and liquid.Very toxic, fuming in the air and publishes a very unpleasant smell.Even couples in low concentrations can cause burns on the skin and irritation of the mucous membranes of the body.If you exceed the permitted limit, it is possible to suffocation and death.
chemical formula of the liquid - Br2.It is obvious that the symbol is formed from the Greek name of the element - bromos.The connection between single atoms, non-polar covalent.The radius of an atom is relatively large, so the bromine reacts quite easily.This allows wide use in the chemical synthesis, often as a reagent for qualitative determination of organic compounds.
As simple substances not found in nature, since it is easily volatilized in the form of a reddish-brown smoke having a corrosive effect.Only in the form of various multicomponent systems.The degree of oxidation of bromine compounds of various kinds depends on the element with which it is to react, that is with some substance.
physical properties
These characteristics can be expressed by a few points.
- Solubility in water - average, but better than the other halogens.Saturated bromine water solution is called, it has a reddish brown color.
- boiling point of liquid - 59.2 0C.
- melting point of -7.25 0C.
- The smell - a sharp, unpleasant, suffocating.
- color - reddish brown.
- Appearance simple substances - heavy (high-density), thick liquid.
- Pauling electronegativity scale - 2.8.
These characteristics affect the production methods of the compound, as well as impose the obligation to comply with extreme caution when working with him.
Chemical properties of bromine
In terms of chemistry, bromine behaves in two ways.Shows and oxidizing and reducing properties.Like all other elements, it is able to accept electrons from the less electronegative metals and non-metals.The reducing agent, he is a strong oxidizing agents, such as:
- oxygen;
- fluorine;
- chlorine;
- some acid.
Naturally, oxidation with bromine ranges from -1 to +7.What exactly is able to react element under consideration?
- with water - the result is a mixture of acids (hypobromous and hydrobromic).
- With various iodide, because bromine is able to displace iodine from its salts.With all
- directly nonmetals other than oxygen, carbon, nitrogen, and noble gases.
- Almost all metals as a strong oxidizing agent.With many substances even with the ignition.
- The OVR bromine reactions often promotes oxidation compounds.For example, sulfur and sulfite converted into sulfate ions, iodine in iodides as a simple substance.
- with alkalis to form bromides, bromates or hypobromate.
particular importance are the chemical properties of bromine, when it is part of the acids and salts, they are educated.In this form very strong properties as the oxidant.It is much more pronounced than that of a simple substance.
Getting
What we are considering the substance important and significant in terms of chemistry, it confirms its annual production in the amount of 550,000 tons.Leading countries on these indicators:
- USA.
- China.
- Israel.
industrial process for the production of free bromine based on the processing of brine lakes, wells, seas.Of these, the salt of the desired element is allocated, which translates into the acidic form.It is passed through a strong flow of air or steam.Thus, a gaseous bromine.Then it was treated with soda ash and a mixture of sodium salts - bromides and bromates.Their solution is acidified and outlet are free liquid material.
Laboratory synthesis methods based on the displacement of bromine with chlorine salts thereof as stronger halogen.
Being in nature
In its pure form we are considering a substance not found in nature, since it is the air of volatile fuming liquid.Basically, a part of the compounds which exhibit a minimum degree of oxidation of bromine -1.It hydrobromic acid salt - bromides.A lot of this element accompanies natural salt chlorine - Silvina, carnallite, and others.
Minerals of bromine were open later than himself.The most common ones are three:
- embolism - a mixture of chlorine and bromine with silver;
- bromarginit;
- bromsilvinit - a mixture of potassium, magnesium and bromine, with the associated water (hydrated).
Also, be sure to include this element in the composition of living organisms.Its deficiency leads to various nervous system diseases, disorders, sleep disorders and memory impairment.In a worst case threatens to infertility.Fish, marine animals are able to accumulate considerable amounts of bromine in the form of salts.
mass in the earth's crust its content reaches 0.0021%.Many contain sea water, and the whole Earth's hydrosphere.
bromine compounds with lower oxidation
What degree of oxidation at the bromine in its compounds with metals and hydrogen?The lowest, which is possible for this item - minus one.It is these compounds and represent the greatest practical interest for the person.
- HBr - hydrogen bromide (gas) or hydrobromic acid.In gaseous aggregate state it has no color, but very sharp and unpleasant smell, a lot of smoke.It has a corrosive effect on the mucous membranes of the body.It is readily soluble in water, forming acid.It, in turn, refers to a strong electrolytes, it is a good reducing agent.It is readily converted to the free bromine by the action of sulfuric acid, nitric acid and oxygen.Industrial importance as a source of bromide ion to form salts with metal cations.
- Bromides - salts of said acid, in which the degree of oxidation as well bromine is -1.Practical interest: LiBr and KBr.
- compounds of organic nature containing bromide ion.
compounds with higher oxidation
These include a few basic materials.The degree of oxidation higher bromine is 7, so these compounds it is just and it should be.
- bromine acid - HBrO4.The strongest of all known acids for this element, but the most stable and to attack by strong reductants.This is due to the special geometric structure of the molecule, which in space is in the form of a tetrahedron.
- Perbromates - salt above indicated acids.For them also typical maximum oxidation bromine.They are strong oxidizing agents, and thus are used in the chemical industry.Examples: NaBrO4, KBrO4.
The use of bromine and its compounds
can designate a few areas in which the bromine and its compounds are direct application.
- production of dyes.
- For making photographs.
- as drugs in medicine (salt bromine).
- In the automotive industry, namely as an additive in gasoline.
- Use as a treatment for lowering the flammability of some organic materials.
- In the manufacture of drilling muds.
- in agriculture in the manufacture of protective insecticide sprayers.
- as disinfectant and decontaminating, including water.
biological effect on the body
the excess and lack of bromine in the body have very unpleasant consequences.
Even Pavlov first to determine the effect of this element on living beings.Animal studies have shown that long-term shortfall of bromide ions leads to:
- malfunction of the nervous system;
- sexual dysfunction;
- miscarriages and infertility;
- growth reduction;
- decrease in hemoglobin levels;
- insomnia and so on.
Excess accumulation in organs and tissues leads to suppression of the work of the brain and spinal cord, various outer skin diseases.
