One of the metals that was discovered quite a long time ago, but to this day has not lost its relevance in use due to its remarkable properties, is zinc. Its physical and chemical properties make it possible to use the material in a wide variety of industries and everyday life. It also has a significant impact on human health.

A Brief History of the Element's Discovery

People knew what zinc was even before our era. After all, it was then that they learned to use alloys containing this metal. The Egyptians used ores containing copper and zinc, smelted them and obtained a very strong, oxidation-resistant material. Household items and dishes made from this material were found.

The name zinc appears in the writings of the physician Paracelsus in the 16th century AD. During the same period, the Chinese began to actively use the metal, casting coins from it. Gradually, knowledge about this substance and its good technical properties is spreading to Europe. Then in Germany and England they also learned what zinc is and where it can be used.

Brass was one of the first and most famous alloys, used since ancient times in Cyprus and later in Germany and other countries.

The name comes from the Latin zincum, but the etymology is not entirely clear. There are several versions.

1. From the German zinke, which translates as "edge".
2. From the Latin zincum, meaning "white coating".
3. Persian "cheng", that is, stone.
4. Old German zinco, which translates as “plaque”, “eyesore”.

The element received its current name only at the beginning of the 20th century. The importance of zinc ions in the human body also became known only relatively recently (20th century). Before this, no ailments were associated with this element.

However, it is known that already in ancient times, many peoples used soups made from young lamb meat as a means of recovery from illness and for a speedy recovery. Today we can say that the effect was achieved due to zinc ions, which this dish contains quite a lot. It helped restore blood circulation, relieve fatigue and activated brain activity.

Element Zinc: characteristics

This element is located in the periodic table in the second group, a secondary subgroup. Serial number 30, mass of Zinc - 65.37. The only and constant oxidation state is +2. Electronic configuration of the outer layer of the 4s 2 atom.

In the table, Zinc, Copper, Cadmium, Chromium, Manganese and many others are transition metals. These include all those whose electrons fill the outer and pre-external d and f energy sublevels.

Zinc salts

Almost all salts that are not double and complex, that is, do not contain foreign colored ions, are colorless. The most popular in terms of human use are the following.

1. Zinc chloride - ZnCL 2. Another name for the compound is soldering acid. Externally, it appears as white crystals that absorb air moisture well. Used to clean the surface of metals before soldering, to obtain fiber, in batteries, to impregnate wood before processing as a disinfectant.
2. Zinc sulfide. White powder, quickly turning yellow when heated. It has a high melting point, unlike pure metal. It is used in the production of luminescent compounds applied to screens, panels and other objects. Is a semiconductor.
3. - a common poison used to get rid of gnawing animals (mice, rats).
4. Smithsonite, or zinc carbonate - ZnCO 3. Colorless crystalline compound, insoluble in water. It is used in petrochemical production, as well as in silk production reactions. It is a catalyst in organic synthesis and is used as a soil fertilizer.
5. Zinc acetate - (CH 3 COO) 2 Zn. Colorless crystals, highly soluble in all solvents of any nature. It is widely used in the chemical, medical and food industries. Used to treat nosopharyngitis. Used as a food additive E650 - freshens breath, prevents the appearance of plaque on teeth when included in chewing gum. It is also used for pickling dyes, preserving wood, producing plastics and other organic syntheses. Almost everywhere it plays the role of an inhibitor.
6. Zinc iodide is a white crystal used in radiography, as an electrolyte in batteries, and as a dye for electron microscopy.
7. Black or dark green crystals that cannot be obtained by direct synthesis, since zinc does not react with nitrogen. Formed from metal ammonia. At high temperatures it decomposes with the release of zinc, therefore it is used for its production.
8. Zinc nitrate. Colorless hygroscopic crystals. Zinc is used in this form in the textile and leather industries for treating fabrics.

Zinc alloys

As mentioned above, the most common zinc alloy is brass. It has been known since ancient times and is still actively used by people to this day. What is he like?

Brass is copper and zinc, which are combined harmoniously with several other metals, giving additional shine, strength and refractoriness to the alloy. Zinc is included as an alloying element, copper as the main one. The color of the material is yellow and shiny, but can turn black in the open air in a humid environment. The melting point is about 950 o C, it can vary depending on the zinc content (the more it is, the lower the temperature).

The material is well rolled into sheets, pipes, and contact welded. It has good technical characteristics, so the following elements are made from it:.

1. Machine parts and various technical devices.
2. Sleeves and stamped products.
3. Nuts, bolts, pipes.
4. Fittings, bushings, anti-corrosion parts for various types of transport.
5. Clock details.

Most of the metal we are considering mined in the world goes specifically to the production of this alloy.

Another type of intermetallic compound is zinc antimonide. Its formula is Zn 4 Sb 3. It is also an alloy that is used as a semiconductor in transistors, thermal imagers, and magnetoresistive devices.

It is obvious that the use of zinc and its compounds is very wide and almost everywhere. This metal is as popular as copper and aluminum, silver and gold, manganese and iron. Its importance is especially great for technical purposes as an anti-corrosion material. After all, various alloys and products are coated with zinc to protect them from this destructive natural process.

Biological role

What is zinc from a medical and biological point of view? Does it matter for the life of organisms and how great is it? It turns out that zinc ions simply must be present in living beings. Otherwise, the deficit will lead to the following consequences:

• anemia;
• decreased insulin;
• allergies;
• weight loss and memory;
• fatigue;
• depression;
• blurred vision;
• irritability and others.

The main places of concentration of zinc ions in the human body are the liver and muscles. It is also this metal that is part of most enzymes (for example, carbonic anhydrase). Therefore, most catalytic reactions occur with the participation of zinc.

What exactly do ions do?

1. Participate in the synthesis of male hormones and seminal fluid.
2. Promotes the absorption of vitamin E.
3. Participate in the breakdown of alcohol molecules in the body.
4. They are direct participants in the synthesis of many hormones (insulin, growth hormone, testosterone and others).
5. Takes part in hematopoiesis and healing of damaged tissues.
6. Regulates the secretion of the sebaceous glands, maintains normal hair and nail growth, and promotes regeneration processes in the skin.
7. It has the ability to eliminate toxins from the body and strengthen the immune system.
8. Affects the formation of taste sensations, as well as the sense of smell.
9. Takes part in transcription processes, vitamin A metabolism, nucleic synthesis and decay.
10. It is a participant in all stages of cell growth and development, and also accompanies the process of gene expression.

All this once again proves how important this metal is. Its role in biological systems was clarified only in the 20th century. Many troubles and illnesses in the past could have been avoided if people had known about treatment with zinc-based drugs.

How can you maintain the required amount of this element in the body? The answer is obvious. It is necessary to consume foods containing zinc. The list can be long, so we will indicate only those with the maximum number of the element in question:

• nuts and seeds;
• legumes;
• meat;
• seafood, especially oysters;
• cereals and bread;
• milk products;
• greens, vegetables and fruits.

Human use

We have already generally indicated in which sectors and areas of industry zinc is used. The price of this metal and its alloys is quite high. For example, a sheet of brass measuring 0.6 x 1.5 is approximately valued at 260 rubles. And this is quite justified, because the quality of the material is quite high.

So, metallic zinc, that is, as a simple substance, is used:

• for anti-corrosion coating on iron and steel products;
• in batteries;
• printing houses;
• as a reducing agent and catalyst in organic syntheses;
• in metallurgy for isolating other metals from their solutions.

It is used not only for cosmetic purposes, which we have already mentioned, but also as a filler in the production of rubber, as a white pigment in paints.

We talked about where various zinc salts are used when considering these compounds. It is obvious that, in general, zinc and its substances are important and significant components in industry, medicine and other fields, without which many processes would be impossible or very difficult.

Zinc is an element of the secondary subgroup of the second group, the fourth period of the periodic system of chemical elements of D.I. Mendeleev, with atomic number 30. It is designated by the symbol Zn (lat. Zincum). The simple substance zinc (CAS number: 7440-66-6) under normal conditions is a brittle transition metal of a bluish-white color (tarnishes in air, becoming covered with a thin layer of zinc oxide).

History and origin of the name

An alloy of zinc and copper - brass - was known in Ancient Greece, Ancient Egypt, India (7th century), China (11th century). For a long time it was not possible to isolate pure zinc. In 1746, A. S. Marggraf developed a method for producing pure zinc by calcining a mixture of its oxide and coal without access of air in clay refractory retorts, followed by condensation of zinc vapor in refrigerators. Zinc smelting began on an industrial scale in the 17th century.
The word "zinc" first appears in the writings of Paracelsus, who called this metal the word "zincum" or "zinken" in the book Liber Mineralium II. This word probably goes back to him. Zinke meaning "tooth" (zinc metal crystals are like needles).

Receipt

Zinc does not occur in nature as a native metal. Zinc is extracted from polymetallic ores containing 1-4% Zn in the form of sulfide, as well as Cu, Pb, Ag, Au, Cd, Bi. Ores are enriched by selective flotation, obtaining zinc concentrates (50-60% Zn) and at the same time lead, copper, and sometimes also pyrite concentrates. Zinc concentrates are fired in fluidized bed furnaces, converting zinc sulfide into ZnO oxide; The resulting sulfur dioxide SO2 is used to produce sulfuric acid. Pure zinc is obtained from ZnO oxide in two ways. According to the pyrometallurgical (distillation) method, which has existed for a long time, the calcined concentrate is subjected to sintering to impart granularity and gas permeability, and then reduced with coal or coke at 1200-1300 °C: ZnO + C = Zn + CO. The resulting metal vapors are condensed and poured into molds. At first, reduction was carried out only in retorts made of baked clay, operated manually, later they began to use vertical mechanized retorts made of carborundum, then - shaft and arc electric furnaces; Zinc is obtained from lead-zinc concentrates in blast furnaces. Productivity gradually increased, but zinc contained up to 3% impurities, including valuable cadmium. Distillation zinc is purified by segregation (that is, by settling the liquid metal from iron and part of the lead at 500 °C), achieving a purity of 98.7%. Sometimes used, more complex and expensive purification by rectification gives the metal a purity of 99.995% and allows the recovery of cadmium.
The main method of obtaining zinc is electrolytic (hydrometallurgical). The roasted concentrates are treated with sulfuric acid; the resulting sulfate solution is cleaned of impurities (by precipitating them with zinc dust) and subjected to electrolysis in baths tightly lined inside with lead or vinyl plastic. Zinc is deposited on aluminum cathodes, from which it is removed (stripped off) daily and melted in induction furnaces. Typically, the purity of electrolytic zinc is 99.95%, the completeness of its extraction from the concentrate (taking into account waste processing) is 93-94%. Zinc sulfate, Pb, Cu, Cd, Au, Ag are obtained from production waste; sometimes also In, Ga, Ge, Tl.

Physical properties

In its pure form it is a rather ductile silvery-white metal. It has a hexagonal lattice with parameters a = 0.26649 nm, c = 0.49431 nm, space group P 6 3 /mmc, Z = 2. At room temperature it is brittle; when the plate is bent, a crack is heard from the friction of crystallites (usually stronger than “ scream of tin"). At 100-150 °C zinc is plastic. Impurities, even minor ones, dramatically increase the fragility of zinc. Intrinsic concentration of charge carriers in zinc 13.1×10 28 m -3

Element zinc(Zn) in the periodic table has serial number 30. It is in the fourth period of the second group. Atomic weight - 65.37. Distribution of electrons across layers 2-8-18-2.

Element 30 of the periodic table Zinc is a bluish-white metal that melts at 419 (C, and at 913 (C) it turns into steam; its density is 7.14 g/cm3. At ordinary temperatures, zinc is quite fragile, but at 100-110 ( It bends well and is rolled into sheets. In air, zinc is coated with a thin layer of oxide or basic carbonate, which protects it from further oxidation. Water has almost no effect on zinc, although it is much to the left of hydrogen in the series of stresses. This is explained by the fact that the formed on the surface of zinc, when it interacts with water, the hydroxide is practically insoluble and prevents the further course of the reaction. In dilute acids, zinc easily dissolves to form the corresponding salts. In addition, zinc, like beryllium and other metals that form amphoteric hydroxides, dissolves in alkalis if zinc is heated. in air to the boiling point, its vapor ignites and burns with a greenish-white flame, forming zinc oxide.

The average zinc content in the earth's crust is 8.3·10-3%; in basic igneous rocks it is slightly higher (1.3·10-2%) than in acidic rocks (6·10-3%). Zinc is an energetic aquatic migrant; its migration in thermal waters along with lead is especially typical. Zinc sulfides, which are of industrial importance, precipitate from these waters. Zinc also migrates vigorously in surface and underground waters; the main precipitant for it is hydrogen sulfide; sorption by clays and other processes play a lesser role.
Zinc is an important biogenic element; living organisms contain an average of 5·10-4% zinc. But there are exceptions - so-called hub organisms (for example, some violets).

Zinc deposits

Zinc deposits are known in Iran, Australia, Bolivia, and Kazakhstan. In Russia, the largest producer of lead-zinc concentrates is JSC MMC Dalpolimetal

Obtaining zinc

Zinc does not occur in nature as a native metal.
Zinc is extracted from polymetallic ores containing 1-4% Zn in the form of sulfide, as well as Cu, Pb, Ag, Au, Cd, Bi. Ores are enriched by selective flotation, obtaining zinc concentrates (50-60% Zn) and at the same time lead, copper, and sometimes also pyrite concentrates. Zinc concentrates are fired in fluidized bed furnaces, converting zinc sulfide into ZnO oxide; The resulting sulfur dioxide SO2 is used to produce sulfuric acid. Pure zinc is obtained from ZnO oxide in two ways. According to the pyrometallurgical (distillation) method, which has existed for a long time, the calcined concentrate is subjected to sintering to impart granularity and gas permeability, and then reduced with coal or coke at 1200-1300 °C: ZnO + C = Zn + CO. The resulting metal vapors are condensed and poured into molds. At first, reduction was carried out only in retorts made of baked clay, operated manually, later they began to use vertical mechanized retorts made of carborundum, then - shaft and arc electric furnaces; Zinc is obtained from lead-zinc concentrates in blast furnaces. Productivity gradually increased, but zinc contained up to 3% impurities, including valuable cadmium. Distillation zinc is purified by segregation (that is, by settling the liquid metal from iron and part of the lead at 500 °C), achieving a purity of 98.7%. The sometimes more complex and expensive purification by rectification produces metal with a purity of 99.995% and allows the recovery of cadmium.

The main method of obtaining zinc is electrolytic (hydrometallurgical). Calcined concentrates are treated with sulfuric acid; the resulting sulfate solution is cleaned of impurities (by precipitating them with zinc dust) and subjected to electrolysis in baths tightly lined inside with lead or vinyl plastic. Zinc is deposited on aluminum cathodes, from which it is removed (stripped off) daily and melted in induction furnaces. Typically, the purity of electrolytic zinc is 99.95%, the completeness of its extraction from the concentrate (taking into account waste processing) is 93-94%. Zinc sulfate, Pb, Cu, Cd, Au, Ag are obtained from production waste; sometimes also In, Ga, Ge, Tl.

Biological role

The adult body contains on average about 2 g of zinc, which is concentrated mainly in the muscles, liver and pancreas. More than 400 enzymes contain zinc. Among them are enzymes that catalyze the hydrolysis of peptides, proteins and esters, the formation of aldehydes, and the polymerization of DNA and RNA. Zn2+ ions in enzymes cause polarization of water molecules and organic substances, promoting their deprotonation according to the reaction:

Zn2+ + H2O = ZnOH+ + H+
The most studied enzyme is carbonic anhydrase, a protein containing zinc and consisting of approximately 260 amino acid residues. This enzyme is found in red blood cells and promotes the conversion of carbon dioxide formed in tissues during their vital activity into bicarbonate ions and carbonic acid, which are transported by the blood to the lungs, where they are excreted from the body in the form of carbon dioxide. In the absence of the enzyme, the conversion of CO2 to the anion HCO3- occurs at a very low rate. In the carbonic anhydrase molecule, the zinc atom is bonded to three imidazole groups of histidine amino acid residues and a water molecule, which is easily deprotonated, turning into a coordinated hydroxide. The carbon atom of the carbon dioxide molecule, which has a partial positive charge, interacts with the oxygen atom of the hydroxyl group. Thus, the coordinated CO2 molecule is converted into a bicarbonate anion, which leaves the active center of the enzyme, being replaced by a water molecule. The enzyme speeds up this hydrolysis reaction by 10 million times.

Applications of zinc

Pure zinc metal is used to recover precious metals mined by underground leaching (gold, silver). In addition, zinc is used to extract silver, gold (and other metals) from crude lead in the form of zinc-silver-gold intermetallic compounds (so-called “silver foam”), which are then processed by conventional refining methods.
It is used to protect steel from corrosion (galvanization of surfaces not subject to mechanical stress, or metallization - for bridges, tanks, metal structures).
Zinc is used as a material for the negative electrode in chemical power sources, that is, in batteries and accumulators, for example: manganese-zinc cell, silver-zinc battery (EMF 1.85 V, 150 Wh / kg, 650 Wh / dm³, low resistance and colossal discharge currents), mercury-zinc element (EMF 1.35 V, 135 Wh/kg, 550-650 Wh/dm³), dioxysulfate-mercury element, zinc iodate element, copper- oxide galvanic cell (EMF 0.7-1.6 Volts, 84-127 Wh/kg, 410-570 Wh/dm³), chromium-zinc cell, zinc-silver chloride cell, nickel-zinc battery (EMF 1 .82 Volt, 95–118 Wh/kg, 230–295 Wh/dm³), lead-zinc cell, zinc-chlorine battery, zinc-bromine battery, etc.

The role of zinc in zinc-air batteries, which have a very high specific energy capacity, is very important. They are promising for starting engines (lead battery - 55 Wh/kg, zinc-air - 220-300 Wh/kg) and for electric vehicles (range up to 900 km).

Zinc plates are widely used in printing, in particular, for printing illustrations in large-circulation publications. For this purpose, zincography has been used since the 19th century - making cliches on a zinc plate by etching the design in it with acid. Impurities, with the exception of a small amount of lead, impair the etching process. Before etching, the zinc plate is annealed and rolled in a heated state.
Zinc is added to many hard solders to reduce their melting point.
Zinc oxide is widely used in medicine as an antiseptic and anti-inflammatory agent. Zinc oxide is also used to produce paint - zinc white.

Zinc- an important component of brass. Zinc alloys with aluminum and magnesium (ZAM, ZAMAK), due to their relatively high mechanical and very high casting qualities, are very widely used in mechanical engineering for precision casting. In particular, in the arms industry, pistol bolts are sometimes cast from the ZAMAK (-3, −5) alloy, especially those designed for the use of weak or traumatic cartridges. Also, all kinds of technical accessories are cast from zinc alloys, such as car handles, carburetor bodies, scale models and all kinds of miniatures, as well as any other products that require precise casting with acceptable strength.

Zinc chloride- an important flux for soldering metals and a component in the production of fiber.
Zinc sulfide is used in the manufacture of short-lasting phosphors and other luminescent compounds, usually mixtures of ZnS and CdS, activated with ions of other metals. Phosphors based on zinc and cadmium sulfides are also used in the electronics industry for the manufacture of luminous flexible panels and screens as electroluminophores and compositions with a short glow time.
Zinc telluride, selenide, phosphide, and sulfide are widely used semiconductors. Zinc sulfide is an integral part of many phosphors. Zinc phosphide is used as a rodent poison.
Zinc selenide is used to make optical glasses with very low absorption coefficients in the mid-infrared region, such as in carbon dioxide lasers.

The different uses of zinc include:

galvanizing - 45-60%
medicine (zinc oxide as an antiseptic) - 10%
production of alloys - 10%
production of rubber tires - 10%
oil paints - 10%

Introduction

Zinc phosphate is a colorless crystal of the orthorhombic system. Density 3.03-3.04 g/cm3. Practically insoluble in water (PR=9.1*10-33). Soluble in acids. The purpose of this course work is to obtain zinc phosphate. To do this, it is necessary to solve the following problems: 1) Select literature and study the properties of Zn, Cd, Hg, Cd 3 (PO 4) 2 Hg 3 (PO 4) 2; consider their history of discovery, distribution in nature; study physical and chemical properties; consider applications and biological role. 2) Select the optimal synthesis method. 3) Synthesize and study the redox properties of Zn 3 (PO 4) 2.

zinc cadmium mercury chemical

Theoretical part

Zinc

History of discovery

Zinc is an element that man has known and used since ancient times. The most common mineral is zinc carbonate, or calamine. Like any carbonate, calamine, when heated, or rather calcined, decomposes into zinc oxide and carbon dioxide. Zinc oxide has been widely used in medicine, for example, in the treatment of eye diseases. Zinc oxide can be easily reduced to free zinc. But it was possible to obtain zinc in the form of a metal much later than the main metals of antiquity were obtained: tin, lead, iron, copper. To reduce zinc from oxide with coal, a temperature of about 1100 °C is required. The boiling point of zinc is only 906 °C. The consequence of this was that the zinc simply evaporated and could not be captured.

Zinc was used by humans to make brass, an alloy of copper and zinc. Brass was used everywhere, in China, India, Greece and Rome. Historians and archaeologists have established that the Romans first received brass. This happened during the reign of Emperor Augustus, at the beginning of our era according to chronology. And this method was used until the 19th century.

It was not possible to determine exactly when the zinc was obtained. In the ruins of Dacia, archaeologists found an idol that contained more than 27% zinc. Presumably, zinc was obtained as a by-product during the production of brass.

The art of obtaining zinc in Europe was lost in the X-XI centuries. But zinc was required to produce brass, so it had to be imported from China and India. The first industrial production was opened in China. But the method was very simple. To obtain zinc, calamine was poured into clay pots, which were tightly closed, folded into a pyramid, the spaces between them were filled with coal and the pots were heated to high temperatures. The pots were heated red hot. After this operation, the pots were cooled, broken, and zinc metal was recovered in the form of ingots.

In Europe, zinc began to be produced again in the 16th century. The task of chemists was to improve methods for producing zinc metal. Huge credit for this belongs to A. Marggraf, who worked on methods for isolating zinc from natural minerals.

The name zinc comes from a similar-sounding Latin word that meant white coating. Although there is another opinion that the name of the metal comes from the German word zinn.

An alloy of zinc and copper - brass - was known in Ancient Greece, Ancient Egypt, India (7th century), China (11th century). For a long time it was not possible to isolate pure zinc. In 1746, A. S. Marggraf developed a method for producing pure zinc by calcining a mixture of its oxide and coal without access of air in clay refractory retorts, followed by condensation of zinc vapor in refrigerators. Zinc smelting began on an industrial scale in the 17th century.
The Latin zincum translates as “white coating.” The origin of this word is not precisely established. Presumably, it comes from the Persian "cheng", although this name does not refer to zinc, but to stones in general. The word "zinc" is found in the works of Paracelsus and other researchers of the 16th and 17th centuries. and goes back, perhaps, to the ancient German “zinc” - plaque, eyesore. The name "zinc" became commonly used only in the 1920s.

Being in nature, receiving:

The most common zinc mineral is sphalerite, or zinc blende. The main component of the mineral is zinc sulfide ZnS, and various impurities give this substance all kinds of colors. Apparently, this is why the mineral is called blende. Zinc blende is considered the primary mineral from which other minerals of element No. 30 were formed: smithsonite ZnCO 3, zincite ZnO, calamine 2ZnO·SiO 2 ·H 2 O. In Altai you can often find striped “chipmunk” ore - a mixture of zinc blende and brown spar. From a distance, a piece of such ore really looks like a hidden striped animal.
Isolation of zinc begins with the concentration of ore using sedimentation or flotation methods, then it is roasted until oxides are formed: 2ZnS + 3O 2 = 2ZnO + 2SO 2
Zinc oxide is processed electrolytically or reduced with coke. In the first case, zinc is leached from the crude oxide with a dilute solution of sulfuric acid, the cadmium impurity is precipitated with zinc dust, and the zinc sulfate solution is subjected to electrolysis. Metal of 99.95% purity is deposited on aluminum cathodes.

Physical properties:

In its pure form it is a rather ductile silvery-white metal. At room temperature it is fragile; when the plate is bent, a cracking sound is heard from the friction of the crystallites (usually stronger than the “cry of tin”). At 100-150 °C zinc is plastic. Impurities, even minor ones, dramatically increase the fragility of zinc. Melting point - 692°C, boiling point - 1180°C

Chemical properties:

A typical amphoteric metal. The standard electrode potential is -0.76 V, in the range of standard potentials it is located up to iron. In air, zinc is coated with a thin film of ZnO oxide. It burns when heated too much. When heated, zinc reacts with halogens, with phosphorus, forming phosphides Zn 3 P 2 and ZnP 2, with sulfur and its analogs, forming various chalcogenides, ZnS, ZnSe, ZnSe 2 and ZnTe. Zinc does not react directly with hydrogen, nitrogen, carbon, silicon and boron. Zn 3 N 2 nitride is produced by the reaction of zinc with ammonia at 550-600°C.
Zinc of ordinary purity reacts actively with solutions of acids and alkalis, in the latter case forming hydroxinates: Zn + 2NaOH + 2H 2 O = Na 2 + H 2
Very pure zinc does not react with solutions of acids and alkalis.
Zinc is characterized by compounds with an oxidation state of +2.

The most important connections:

Zinc oxide- ZnO, white, amphoteric, reacts with both acid solutions and alkalis:
ZnO + 2NaOH = Na 2 ZnO 2 + H 2 O (fusion).
Zinc hydroxide- forms as a gelatinous white precipitate when alkali is added to aqueous solutions of zinc salts. Amphoteric hydroxide
Zinc salts. Colorless crystalline substances. In aqueous solutions, zinc ions Zn 2+ form aqua complexes 2+ and 2+ and undergo severe hydrolysis.
Zincates are formed by the interaction of zinc oxide or hydroxide with alkalis. When fused, metazincates are formed (for example, Na 2 ZnO 2), which, dissolving in water, turn into tetrahydroxo zincates: Na 2 ZnO 2 + 2H 2 O = Na 2. When solutions are acidified, zinc hydroxide precipitates.

Application:

Production of anti-corrosion coatings. - Metallic zinc in the form of bars is used to protect against corrosion of steel products in contact with sea water. Approximately half of all zinc produced is used in the production of galvanized steel, one third in hot-dip galvanizing of finished products, and the rest for strip and wire.
- Zinc-brass alloys (copper plus 20-50% zinc) are of great practical importance. In addition to brass, a rapidly growing number of special zinc alloys are used for die casting.
- Another area of ​​application is the production of dry cell batteries, although this has decreased significantly in recent years.
- Zinc telluride ZnTe is used as a material for photoresistors, infrared radiation receivers, dosimeters and radiation counters. - Zinc acetate Zn(CH 3 COO) 2 is used as a fixative for dyeing fabrics, a wood preservative, an antifungal agent in medicine, and a catalyst in organic synthesis. Zinc acetate is a component of dental cements and is used in the production of glazes and porcelain.

Zinc is one of the most important biologically active elements and is essential for all forms of life. Its role is due mainly to the fact that it is part of more than 40 important enzymes. The function of zinc in proteins responsible for recognizing the sequence of bases in DNA and, therefore, regulating the transfer of genetic information during DNA replication has been established. Zinc is involved in carbohydrate metabolism with the help of the zinc-containing hormone insulin. Vitamin A is effective only in the presence of zinc. Zinc is also necessary for bone formation.
At the same time, zinc ions are toxic.

Bespotestnykh S., Shtanova I.
HF Tyumen State University, 571 group.

Sources: Wikipedia: