Phosphorus consists of a substance with density. White phosphorus: properties, history of discovery and application

Phosphorus

PHOSPHORUS-A; m.[from Greek phōsphoros - luminous] A chemical element (P) that plays an important role in the life of animals and plants (found in some minerals, animal bones, animal and plant tissues). Red f. Black f. Fish contains a lot of phosphorus. F. is needed to strengthen bones. White f.(flammable and glow-in-the-dark substance). The sea glows, shines with phosphorus(glows greenish at night due to the abundance of microorganisms).

◁ Phosphorus (see).

(lat. Phosphorus), chemical element of group V of the periodic table. Named from the Greek. phōsphóros - luminous. Forms several modifications - white phosphorus (density 1.828 g/cm 3, t pl 44.14°C), red phosphorus (density 2.31 g/cm 3, t mp 593°C), etc. White phosphorus is self-igniting, glows in the dark (hence the name), and poisonous; red is less chemically active and poisonous. It is mined from apatites and phosphorites. The main consumer is agriculture (phosphorus fertilizers); used in match production, metallurgy (deoxidizer and component of some alloys), in organic synthesis, etc. Present in living cells in the form of ortho- and pyrophosphoric acids and their derivatives.

PHOSPHORUS (Latin - Phoshopus), P (read "pe"), chemical element with atomic number 15, atomic weight 30.973762. Located in group VA in the 3rd period of the periodic table. Has one stable nuclide 31 R. Outer electron layer configuration 3 s 2 R 3 . In compounds it exhibits oxidation states from –3 to +5. Valences from III to V. The most stable oxidation state in compounds is +5.
The radius of the neutral atom P is 0.134 nm, the radius of the ions is: P 3- 0.186 nm, P 3+ 0.044 nm (coordination number 6) and P 5+ - 0.017 nm (coordination number 4) and 0.038 nm (coordination number 6). The sequential ionization energies of the neutral P atom are 10.486, 19.76, 30.16, 51.4 and 65 eV. Electron affinity 0.6 eV. Electronegativity according to Pauling (cm. PAULING Linus) 2.10. Non-metal.
History of discovery
The first to obtain phosphorus in a free state was the Hamburg alchemist H. Brand in 1669 (there is information that a substance with similar properties was obtained in the 12th century by the Arab alchemist Behil). In search of the philosopher's stone (cm. ELIXIR) he calcined the dry residue from the evaporation of urine with river sand and charcoal in a closed vessel. After calcination, the vessel with the reagents began to glow in the dark with white light (this was phosphorus, reduced from its compounds contained in urine).
In 1680, phosphorus glowing in the dark (from the Greek “phosphoros” - luminiferous) was obtained by the Englishman R. Boyle. (cm. BOYLE Robert) In subsequent years, it was found that phosphorus is contained not only in urine, but also in brain tissue and skeletal bones. The simplest method for producing phosphorus by calcining bone ash with coal was proposed in 1771 by K. Scheele (cm. SCHEELE Karl Wilhelm). The elemental nature of phosphorus was established at the end of the 18th century by A. L. Lavoisier. (cm. LAVOISIER Antoine Laurent)
Being in nature
The content in the earth's crust is 0.105% by weight, which significantly exceeds the content of, for example, nitrogen (cm. NITROGEN). In sea water 0.07 mg/l. Phosphorus is not found in free form in nature, but it is part of 200 different minerals. The most famous are phosphorite (cm. PHOSPHORITES) calcium Ca 3 (PO 4) 3, apatites (cm. APATITE)(fluorapatite 3Ca 3 (PO 4) 3 CaF 2, or Ca 5 (PO 4) 3 F), monazite (cm. MONAZITE), turquoise (cm. TURQUOISE). Phosphorus is part of all living organisms.
Receipt
The production of phosphorus is carried out by its electrothermal reduction from phosphorites and apatites at 1400-1600°C with coke in the presence of silica:
2Ca 3 (PO 4) 2 + 6SiO 2 + 10C = P 4 + 6CaSiO 3 + 10CO
4Ca 5 (PO 4) 3 F +21SiO 2 +30C = 3P 4 + 20CaSiO 3 + 30CO + SiF 4
The released P4 vapors are then treated with superheated water steam to produce thermal phosphoric acid H3PO4:
P 4 + 14H 2 O = 4H 3 PO 4 + 8H 2
When P4 vapor desublimates, white phosphorus is formed. It is processed into red phosphorus by heating without access of air at a temperature of 200-300°C in reactors equipped with a screw grinder of the reaction mass.
Features of the structure of allotropic modifications and their physical properties
Elemental phosphorus exists in several allotropic modifications, the main of which are: white (phosphorus III), red (phosphorus II) and black (phosphorus I).
White phosphorus is a waxy, transparent substance with a characteristic odor. Consists of tetrahedral P4 molecules that can rotate freely. White phosphorus has a cubic crystal lattice of molecular type, cell parameter A= 1.851 nm. Density 1.828 kg/dm3. Melting point 44.14°C, boiling point 287°C. There are two forms of white phosphorus: the a-modification, with a cubic crystal lattice, at –76.9°C transforms into the b-modification, the crystal lattice of which is not established and there is no free rotation of P4 molecules. Dielectric. Dissolves in ethyl alcohol, benzene, carbon disulfide CS 2.
By heating white phosphorus without air access at 250-300°C, red phosphorus is obtained. Impurities of sodium, iodine and selenium and UV rays accelerate the transition of one modification to another.
Red phosphorus is amorphous, ranging in color from scarlet to dark brown and violet. There are several crystalline forms with different properties. Crystalline red phosphorus (Hittorf phosphorus) is obtained by cooling a solution of red phosphorus in molten lead saturated at a temperature of 600°C. It has a monoclinic lattice, unit cell parameters A= 1.02 nm, V= 0.936 nm, With= 2.51 nm, angle b 118.8°. The density of red phosphorus is 2.0-2.4 kg/dm3. Dielectric. When heated, red phosphorus evaporates in the form of P4 molecules, the condensation of which leads to the formation of white phosphorus.
When white phosphorus is heated to 200-220°C under a pressure of 1.2 GPa, crystalline black phosphorus is formed. The lattice is constructed of fibrous layers with a pyramidal arrangement of atoms. The most stable variety of black phosphorus has an orthorhombic lattice, parameters A= 0.3314 nm, V= 0.4376 nm, s = 1.0478 nm. The density of black phosphorus is 2.702 kg/dm3. Externally similar to graphite; semiconductor, diamagnetic. When heated to 560-580°C it turns into red phosphorus. Black phosphorus is inactive and difficult to ignite.
Chemical properties
Phosphorus in compounds is mainly covalent. Phosphorus has free 3d orbitals, which leads to the formation of donor-acceptor bonds. White phosphorus is the most active. It oxidizes in air. Oxidation occurs by the mechanism of chain reactions and is accompanied by chemiluminescence. When phosphorus burns in excess oxygen, P 2 O 5 is obtained, which forms P 4 O 10 dimers and P 8 O 20 tetramers. With a lack of oxygen, P 2 O 3 is obtained. Self-ignites in air due to the heat released during oxidation. Red phosphorus oxidizes slowly in air and does not spontaneously ignite. Black phosphorus does not oxidize in air.
Phosphorus(V) oxide is an acidic oxide. It reacts with water, releasing a large amount of heat. In this case, polymeric metaphosphoric acid (HPO 3) n is first formed. When treated with hot water, it turns into tribasic orthophosphoric acid of medium strength H 3 PO 4:
P 4 O 10 + 2H 2 O = (NPO 3) 4; (NPO 3) 4 + 4H 2 O = 4H 3 PO 4
or P 2 O 5 + 3H 2 O = 2H 3 PO 4
Phosphorus reacts with halogens, releasing a large amount of heat. With F, Cl, Br it forms trihalides and pentahalides, with I - only triodide PI 3. All phosphorus halides are easily hydrolyzed to orthophosphoric H 3 PO 4, phosphorous H 3 PO 3 and hydrohalic acids:
PCl 5 + 4H 2 O = H 3 PO 4 + 5HCl
PI 3 + 3H 2 O = H 3 PO 3 + 3HI
Phosphorus trihalides are a trihedral pyramid with halogen atoms at the base and a phosphorus atom at the apex. The pentahalide molecule consists of two trihedral pyramids that have a common face. Phosphorus oxyhalides POF 3, POCl 3 and POBr 3 were obtained.
With sulfur, phosphorus forms the sulfides P 4 S 3, P 4 S 5, P 4 S 7, P 4 S 10. The following phosphorus oxysulfides are known: P 2 O 3 S 2 , P 2 O 2 S 3 , P 4 O 4 S 3 , P 6 O 10 S 5 , P 4 O 4 S 3 . Phosphorus reacts with Se and Te and forms compounds with Si and C (PC 3).
Does not react directly with hydrogen. When interacting with a dilute solution of potassium hydroxide KOH, gaseous phosphine PH 3 is formed:
4P + 3KON +3N 2 O = 3KN 2 RO 2 + RN 3
Diphosphine R 2 H 4 is also formed as an impurity. Both phosphines have a characteristic rotten fish odor.
Phosphine PH 3 has chemical properties similar to ammonia NH 3, but is less stable.
Phosphorus reacts with metals when fused. With alkaline earths it forms ionic phosphides M 3 R 2, which decompose upon contact with water:
Mg 3 P 2 + 6H 2 O = 3Mg(OH) 2 + 2PH 3,
Ca 3 P 2 + 6H 2 O = 3Ca(OH) 2 + 2PH 3
With transition metals, phosphorus forms metal-like phosphides Mn 3 P, FeP, Ni 2 P.
Phosphorus is part of inorganic acids. This is orthophosphoric acid H 3 PO 4 (its salts are orthophosphates, monohydrogen phosphates, Na 2 HPO 4 and dihydrogen phosphates, Ca(H 2 PO 4) 2); metaphosphoric acid (HPO 3) n(its salts are metaphosphates), monobasic hypophosphorous acid H 3 PO 2 (its salts are hypophosphites, NaH 2 PO 2), dibasic phosphorous acid H 3 PO 3 (its salts are phosphites, Na 2 HPO 3).
Phosphorus is part of organic esters, alcohols and acids: phosphinic RRP(O)OH, phosphonic RH 2 PO 2 and phosphonic RP(O)(OH) 2, where R and R are organic radicals.
Application
White phosphorus is used in the production of phosphoric acid H 3 PO 4 (for the production of food phosphates and synthetic detergents). It is used in the manufacture of incendiary and smoke shells and bombs.
Red phosphorus is used in the manufacture of mineral fertilizers and match production. Phosphorus is used in the production of non-ferrous metal alloys as a deoxidizer and serves as an alloying additive. It is used in the production of soft magnetic alloys and in the production of semiconductor phosphides. Phosphorus compounds serve as starting materials for the production of medicines.
Content in the body
Phosphorus is present in living cells in the form of ortho- and pyrophosphoric acids, and is part of nucleotides, nucleic acids, phosphoproteins, phospholipids, coenzymes, and enzymes. Human bones consist of hydroxyapatite 3Ca 3 (PO 4) 3 ·CaF 2. The composition of tooth enamel includes fluorapatite. The liver plays the main role in the transformation of phosphorus compounds in the body of humans and animals. The metabolism of phosphorus compounds is regulated by hormones and vitamin D. The daily human need for phosphorus is 1-2 g. With a lack of phosphorus in the body, various bone diseases develop.
Physiological action
Phosphorus compounds are toxic. The lethal dose of white phosphorus is 50-150 mg. When white phosphorus gets on the skin, it causes severe burns. The chemical warfare agents sarin, soman, and tabun are phosphorus compounds. Acute phosphorus poisoning is manifested by a burning sensation in the mouth and stomach, headache, weakness, and vomiting. After 2-3 days, jaundice develops. Chronic forms are characterized by calcium metabolism disorders and damage to the cardiovascular and nervous systems. First aid for acute poisoning is gastric lavage, laxatives, cleansing enemas, intravenous glucose solutions. For skin burns, treat the affected areas with solutions of copper sulfate or soda. The maximum permissible concentration for phosphorus vapors in the air is 0.03 mg/m3. Red phosphorus dust gets into the lungs and causes pneumonia.

encyclopedic Dictionary. 2009 .

See what “phosphorus” is in other dictionaries:

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- (Phosphorus), P, chemical element of group V of the periodic table, atomic number 15, atomic mass 30.97376; non-metal white (glows in air, melting point 44.14°C), red (melting temperature 593°C) or black (melting temperature 1000°C). Phosphorus is used in... ... Modern encyclopedia

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Phosphorus- (Phosphorus), P, chemical element of group V of the periodic table, atomic number 15, atomic mass 30.97376; non-metal white (glows in air, melting point 44.14°C), red (melting point 593°C) or black (melting temperature 1000°C). Phosphorus is used in... ... Illustrated Encyclopedic Dictionary

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Ipi Lucifer Prosphorus, Lucifer), i.e. light carrier. The name of the planet Venus as the morning star. As the evening star she was called Hesperus, or Vesper, and was considered the son of Astraeus and Eos, the father of the Hesperides. (

Phosphorus (from the Greek phosphoros - luminiferous; lat. Phosphorus) is an element of the periodic system of chemical elements of the periodic table, one of the most common elements of the earth's crust, its content is 0.08-0.09% of its mass. Concentration in seawater is 0.07 mg/l. It is not found in a free state due to its high chemical activity. It forms about 190 minerals, the most important of which are apatite Ca 5 (PO 4) 3 (F,Cl,OH), phosphorite Ca 3 (PO 4) 2 and others. Phosphorus is found in all parts of green plants, even more in fruits and seeds (see phospholipids). Contained in animal tissues, it is part of proteins and other essential organic compounds (ATP, DNA), and is an element of life.

Story

Phosphorus was discovered by the Hamburg alchemist Hennig Brand in 1669. Like other alchemists, Brand tried to find the philosopher's stone, but received a luminous substance. Brand focused on experiments with human urine because he believed that, being golden in color, it might contain gold or something useful for mining. Initially, his method was to first let the urine sit for several days until the unpleasant odor disappeared, and then boil it until it became sticky. By heating this paste to high temperatures and causing bubbles to appear, he hoped that when they condensed, they would contain gold. After several hours of intense boiling, grains of a white wax-like substance were obtained, which burned very brightly and also shimmered in the dark. Brand named this substance phosphorus mirabilis (Latin for “miraculous bearer of light”). Brand's discovery of phosphorus was the first discovery of a new element since antiquity.
Somewhat later, phosphorus was obtained by another German chemist, Johann Kunkel.
Regardless of Brand and Kunkel, phosphorus was obtained by R. Boyle, who described it in the article “Method of preparing phosphorus from human urine,” dated October 14, 1680 and published in 1693.
An improved method for producing phosphorus was published in 1743 by Andreas Marggraf.
There is evidence that Arab alchemists were able to obtain phosphorus in the 12th century.
Lavoisier proved that phosphorus is a simple substance.

origin of name

In 1669, Henning Brand, by heating a mixture of white sand and evaporated urine, obtained a substance that glowed in the dark, first called “cold fire.” The secondary name “phosphorus” comes from the Greek words “φῶς” - light and “φέρω” - carry. In ancient Greek mythology, the name Phosphorus (or Eosphorus, ancient Greek Φωσφόρος) was borne by the guardian of the Morning Star.

Receipt

Phosphorus is obtained from apatites or phosphorites as a result of interaction with coke and silica at a temperature of 1600 ° C:
2Ca 3 (PO 4) 2 + 10C + 6SiO 2 → P4 + 10CO + 6CaSiO 3.

The resulting white phosphorus vapors are condensed in a receiver under water. Instead of phosphorites, other compounds can be reduced, for example, metaphosphoric acid:
4HPO 3 + 12C → 4P + 2H 2 + 12CO.

Physical properties

Elemental phosphorus under normal conditions represents several stable allotropic modifications; The issue of phosphorus allotropy is complex and not fully resolved. Usually there are four modifications of a simple substance - white, red, black and metallic phosphorus. Sometimes they are also called the main allotropic modifications, implying that all the others are a variety of these four. Under normal conditions, there are only three allotropic modifications of phosphorus, and under ultra-high pressure conditions there is also a metallic form. All modifications differ in color, density and other physical characteristics; There is a noticeable tendency towards a sharp decrease in chemical activity during the transition from white to metallic phosphorus and an increase in metallic properties.

Chemical properties

The chemical activity of phosphorus is much higher than that of nitrogen. The chemical properties of phosphorus are largely determined by its allotropic modification. White phosphorus is very active; in the process of transition to red and black phosphorus, the chemical activity decreases sharply. White phosphorus glows in the dark in air; the glow is due to the oxidation of phosphorus vapor to lower oxides.
In liquid and dissolved states, as well as in vapors up to 800 ° C, phosphorus consists of P 4 molecules. When heated above 800 °C, the molecules dissociate: P 4 = 2P 2. At temperatures above 2000 °C, molecules break down into atoms.

Phosphorus was discovered in 1669 by the Hamburg alchemist Hennig Brand, who experimented with the evaporation of human urine in an attempt to obtain the philosopher's stone. The substance formed after numerous manipulations turned out to be similar to wax, burning unusually brightly, with flickering. The new substance was given a name phosphorus mirabilis(from Latin miraculous fire bearer). A few years later, phosphorus was obtained by Johann Kunkel, and also, independently of the first two scientists, by R. Boylem.

Phosphorus is an element of group XV of period III of the periodic table of chemical elements D.I. Mendeleev, with atomic number 15 and atomic mass 30.974. The accepted designation is R.

Being in nature

Phosphorus is found in sea water and the earth's crust mainly in the form of minerals, of which there are about 190 (the most important are apatite and phosphorite). It is part of all parts of green plants, proteins, and DNA.

Phosphorus is a non-metal with high chemical activity and is practically never found in free form. There are four known modifications of phosphorus - red, white, black and metallic.

Daily phosphorus requirement

For normal functioning, the adult body must receive 1.0-2.0 g of phosphorus per day. For children and adolescents, the norm is 1.5-2.5 g, for pregnant and lactating women it increases to 3.0-3.8 g (calorizator). The daily requirement for phosphorus increases during regular sports training and physical activity.

The main suppliers of phosphorus are fish and seafood, cottage cheese, cheese, nuts, legumes and cereals. A sufficient amount of phosphorus is contained in both, and, berries, mushrooms and meat, and.

Signs of phosphorus deficiency

An insufficient amount of phosphorus in the body is characterized by fatigue and weakness, and may be accompanied by loss of appetite and attention, frequent colds, anxiety and a feeling of fear.

Signs of excess phosphorus

Signs of excess phosphorus in the body are bleeding and hemorrhage, anemia develops, and kidney stones occur.

Phosphorus ensures normal growth of bone and dental tissues of the body, maintains them in a healthy state, is also involved in protein synthesis, and plays an important role in the metabolism of fats, proteins and carbohydrates. Without phosphorus, muscles cannot function and mental activity does not occur.

Phosphorus digestibility

When taking mineral complexes, it is worth remembering the best balance of phosphorus and (3:2), as well as the fact that excessive amounts slow down the process of phosphorus absorption.

Phosphorus is widely used in industry and agriculture, primarily due to its flammability. It is used in the production of fuel, matches, explosives, phosphate fertilizers and the protection of metal surfaces from corrosion.

• Designation - P (Phosphorus);
• Period - III;
• Group - 15 (Va);
• Atomic mass - 30.973761;
• Atomic number - 15;
• Atomic radius = 128 pm;
• Covalent radius = 106 pm;
• Electron distribution - 1s 2 2s 2 2p 6 3s 2 3p 3 ;
• melting temperature = 44.14°C;
• boiling point = 280°C;
• Electronegativity (according to Pauling/according to Alpred and Rochow) = 2.19/2.06;
• Oxidation state: +5, +3, +1, 0, -1, -3;
• Density (no.) = 1.82 g/cm 3 (white phosphorus);
• Molar volume = 17.0 cm 3 /mol.

Phosphorus compounds:

Phosphorus (the bringer of light) was first obtained by the Arab alchemist Ahad Behil in the 12th century. Of the European scientists, the first to discover phosphorus was the German Hennig Brant in 1669, while conducting experiments with human urine in an attempt to extract gold from it (the scientist believed that the golden color of urine was caused by the presence of gold particles). Somewhat later, phosphorus was obtained by I. Kunkel and R. Boyle - the latter described it in his article “Method of preparing phosphorus from human urine” (October 14, 1680; the work was published in 1693). Lavoisier later proved that phosphorus is a simple substance.

The phosphorus content in the earth's crust is 0.08% by weight - this is one of the most common chemical elements on our planet. Due to its high activity, phosphorus in a free state does not occur in nature, but is part of almost 200 minerals, the most common of which are apatite Ca 5 (PO 4) 3 (OH) and phosphorite Ca 3 (PO 4) 2.

Phosphorus plays an important role in the life of animals, plants and humans - it is part of such biological compounds as phospholipids, and is also present in proteins and other important organic compounds such as DNA and ATP.

Rice. The structure of the phosphorus atom.

The phosphorus atom contains 15 electrons and has an electronic configuration of the outer valence level similar to nitrogen (3s 2 3p 3), but phosphorus has less pronounced nonmetallic properties compared to nitrogen, which is explained by the presence of a free d-orbital, a larger atomic radius and lower ionization energy .

When reacting with other chemical elements, the phosphorus atom can exhibit an oxidation state from +5 to -3 (the most typical oxidation state is +5, the rest are quite rare).

• +5 - phosphorus oxide P 2 O 5 (V); phosphoric acid (H 3 PO 4); phosphates, halides, sulfides of phosphorus V (salts of phosphoric acid);
• +3 - P 2 O 3 (III); phosphorous acid (H 3 PO 3); phosphites, halides, sulfides of phosphorus III (salts of phosphorous acid);
• 0 - P;
• -3 - phosphine PH 3; metal phosphides.

In the ground (unexcited) state of the phosphorus atom at the outer energy level there are two paired electrons in the s-sublevel + 3 unpaired electrons in p-orbitals (the d-orbital is free). In the excited state, one electron moves from the s-sublevel to the d-orbital, which expands the valence capabilities of the phosphorus atom.

Rice. Transition of the phosphorus atom to an excited state.

P2

Two phosphorus atoms combine to form a P2 molecule at a temperature of about 1000°C.

At lower temperatures, phosphorus exists in tetraatomic P4 molecules as well as in more stable polymer P∞ molecules.

Allotropic modifications of phosphorus:

• White phosphorus- extremely toxic (the lethal dose of white phosphorus for an adult is 0.05-0.15 g) waxy substance with the smell of garlic, colorless, luminescent in the dark (the process of slow oxidation in P 4 O 6); the high reactivity of white phosphorus is explained by weak P-P bonds (white phosphorus has a molecular crystal lattice with the formula P 4, in the nodes of which phosphorus atoms are located), which break quite easily, as a result of which white phosphorus, when heated or during long-term storage, turns into more stable polymer modifications: red and black phosphorus. For these reasons, white phosphorus is stored without access to air under a layer of purified water or in special inert environments.
• Yellow phosphorus- a flammable, highly toxic substance, does not dissolve in water, easily oxidizes in air and ignites spontaneously, while burning with a bright green, dazzling flame with the release of thick white smoke.
• Red phosphorus- a polymeric, water-insoluble substance with a complex structure that has the least reactivity. Red phosphorus is widely used in industrial production, because it is not so poisonous. Since in the open air red phosphorus, absorbing moisture, gradually oxidizes to form a hygroscopic oxide (“damp”) and forms viscous phosphoric acid, therefore, red phosphorus is stored in a hermetically sealed container. In the case of soaking, red phosphorus is cleaned of phosphoric acid residues by washing with water, then dried and used for its intended purpose.
• Black phosphorus- a greasy-to-touch graphite-like substance of gray-black color, with semiconductor properties - the most stable modification of phosphorus with average reactivity.
• Metallic phosphorus obtained from black phosphorus under high pressure. Metallic phosphorus conducts electricity very well.

Chemical properties of phosphorus

Of all the allotropic modifications of phosphorus, the most active is white phosphorus (P 4). Often in the equation of chemical reactions we write simply P, not P4. Since phosphorus, like nitrogen, has many variants of oxidation states, in some reactions it is an oxidizing agent, in others it is a reducing agent, depending on the substances with which it interacts.

Oxidative Phosphorus exhibits its properties in reactions with metals that occur when heated to form phosphides:
3Mg + 2P = Mg 3 P 2.

Phosphorus is reducing agent in reactions:

• with more electronegative nonmetals (oxygen, sulfur, halogens):
  • Phosphorus (III) compounds are formed when there is a lack of oxidizing agent
    4P + 3O 2 = 2P 2 O 3
  • phosphorus compounds (V) - with excess: oxygen (air)
    4P + 5O 2 = 2P 2 O 5
• with halogens and sulfur, phosphorus forms halides and sulfide of 3- or 5-valent phosphorus, depending on the ratio of reagents, which are taken in deficiency or excess:
  • 2P+3Cl 2 (week) = 2PCl 3 - phosphorus (III) chloride
  • 2P+3S(week) = P 2 S 3 - phosphorus (III) sulfide
  • 2P+5Cl2(g) = 2PCl 5 - phosphorus chloride (V)
  • 2P+5S(g) = P 2 S 5 - phosphorus sulfide (V)
• with concentrated sulfuric acid:
  2P+5H 2 SO 4 = 2H 3 PO 4 +5SO 2 +2H 2 O
• with concentrated nitric acid:
  P+5HNO 3 = H 3 PO 4 +5NO 2 +H 2 O
• with dilute nitric acid:
  3P+5HNO 3 +2H 2 O = 3H 3 PO 4 +5NO

Phosphorus acts as both an oxidizing agent and a reducing agent in reactions disproportionation with aqueous solutions of alkalis when heated, forming (except for phosphine) hypophosphites (salts of hypophosphorous acid), in which it exhibits an uncharacteristic oxidation state of +1:
4P 0 +3KOH+3H 2 O = P -3 H 3 +3KH 2 P +1 O 2

YOU MUST REMEMBER: phosphorus does not react with other acids, except for the reactions indicated above.

Production and use of phosphorus

Phosphorus is produced industrially by reducing it with coke from phosphorites (fluorapatates), which include calcium phosphate, by calcining them in electric furnaces at a temperature of 1600°C with the addition of quartz sand:
Ca 3 (PO 4) 2 + 5C + 3SiO 2 = 3CaSiO 3 + 2P + 5CO.

In the first stage of the reaction, under the influence of high temperature, silicon (IV) oxide displaces phosphorus (V) oxide from the phosphate:
Ca 3 (PO 4) 2 + 3SiO 2 = 3CaSiO 3 + P 2 O 5.

Phosphorus (V) oxide is then reduced by coal to free phosphorus:
P 2 O 5 +5C = 2P+5CO.

Application of phosphorus:

• pesticides;
• matches;
• detergents;
• paints;
• semiconductors.

The message on the topic “Use of Phosphorus” will briefly tell you in which areas phosphorus is used and why.

Applications of phosphorus

Phosphorus is a chemical element that is located in group V in the periodic table of Mendeleev. Its chemical formula is R. The name of the element comes from the Greek word “phosphoros” and means “luminiferous”. There is quite a lot of it in the earth's crust - 0.08-0.09% of the total mass of the Earth's crust. There is also phosphorus in sea water. The element has high chemical activity, so you will not find it in a free state. It is capable of forming 190 minerals. It is also called the element of life, as it is found in animal tissues, green plants, proteins, and so on.

Use of phosphorus in medicine

Today, phosphorus is used to produce a class of potential therapeutic agents that treat diseases of soft tissues and bones accompanied by calcium metabolism disorders—biosphosphonates.

Each element has its own spectrum of activity. They are resistant to enzymatic hydrolysis, have an affinity for metal ions, and form insoluble and soluble chelate aggregates and complexes.

The most common and used is etidronate. It is effective for disorders of calcium metabolism in the body. It is used for progressive myositis ossificans, Paget's disease, osteoporosis, heterogeneous ossification and tumor osteolysis.

Application of phosphorus in industry

Phosphoric acid is widely used. It is used for the production of combined and phosphate fertilizers, which increase crop yields and give plants resistance to adverse climatic conditions and winter hardiness. In addition, fertilizers have an excellent effect on the soil, promoting structuring, changing the solubility of substances contained in the soil, the development of soil bacteria, and suppressing the formation of organic harmful substances.

Phosphoric acid is also used in the food industry. It tastes good and, when diluted, is added to marmalade, lemonade, and syrups to improve taste. Phosphoric acid salts have similar properties. For example, calcium hydrogen phosphates are a component of baking powders and enhance the taste of bread and rolls.

Phosphoric wood non-combustible boards, fire-retardant paints, and phosphate non-combustible foam are produced on the basis of orthophosphoric acid. Phosphoric acid salts protect against radiation, soften water, remove boiler scale and are included in detergents.

Organophosphorus compounds (plasticizers, extractants, lubricants, absorbents) are used in refrigeration units and as an additive to gunpowder. Alkyl phosphates act as surfactants, antifreeze, special fertilizers, and latex anticoagulants.

Matches are made from red phosphorus. Together with glue and crushed glass, it is applied to the sides of the matchbox. Zinc phosphide (Zn 3 P 2) is used to control rodents. White phosphorus is used to produce incendiary bombs, smoke-producing shells, checkers, grenades, and smoke screens.

Use of phosphorus in everyday life

In everyday life we ​​are also surrounded by things made of phosphorus. For example, dishes, figurines, vases and the like. In addition, it is an important element that is part of nucleic acids, proteins, and bone tissue. Phosphorus is an important element for muscle and mental activity. Has a beneficial effect on the kidneys and heart. It is found in bread, fish, meat, peas, beans, pearl barley, oatmeal and barley, cabbage, nuts, parsley, carrots, spinach and garlic.

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