See what "Nickel" is in other dictionaries. See what “Nickel” is in other dictionaries Use of nickel and its compounds

"Complex nickel compounds and their properties."

The work was compiled by 2nd year students of group 5202

Nikitin Dmitry and Sharkhemullin Emil.

Kazan 2014

Nickel complex compounds.

The binding of Nickel into complexes is an important process for analytical chemistry in the case of diagnostics and determination of the characteristic properties of substances and the element itself.

1.Complex compound of monovalent nickel

A limited number of them are known, while most are unstable and easily erode in the air; the compounds are colored predominantly red, obtained by the reduction of nickel (II) compounds such as - Nickel (II) oxide NiO, Nickel (II) hydroxide Ni(OH)2, Nickel (II) sulfide NiS). These include K2, Na2, K3, K2, - red.

2. Complex compounds of divalent nickel

These are the most important and stable nickel compounds.

The salts of strong acids formed by the divalent Ni2+ cation are almost all highly soluble in water, and their solutions exhibit a slightly acidic reaction due to hydrolysis. Sparingly soluble salts include salts of relatively weak acids, in particular derivatives of the CO32- and PO43- anions. The hydrated Ni·· ion will be colored bright green. The same color is characteristic of the crystalline salt hydrates formed by it. On the contrary, in the anhydrous state, individual complex salts are colored differently, and their colors do not always coincide with the intrinsic color of Ni2+ (yellow), but also depend on the nature of the anion.

A cation with a given valence (Ni 2+) forms a hexaammine complex 2+ and a diaquatetraammine complex 2+ with ammonia. These complexes with anions form blue or violet compounds, which greatly simplifies their diagnosis.

Aqueous solutions of nickel(II) salts contain hexaaquanickel(II) 2+ ion. When an ammonia solution is added to a solution containing these ions, nickel(II) hydroxide, a green, gelatinous substance, precipitates. This precipitate dissolves when excess ammonia is added due to the formation of hexamminnickel(II) 2+ ions.

In some nickel ammonia there are 2+ and 2+ ions. Compounds derived from these and other nickel ammonia ions are readily soluble in water. The formation of these complexes explains the solubility in an aqueous solution of ammonia of many nickel compounds that are insoluble in pure water, for example, its hydroxide and phosphate

Nickel is also very prone to the formation of intracomplex salts. These include salts in which a metal atom that has replaced hydrogen, for example nickel, is simultaneously linked by a coordination bond to another acidic residue. Intracomplex salts are often characterized by extremely low solubility. For this reason, they have recently become increasingly important in analytical chemistry. One of the most well-known representatives of this class of complex compounds is nickel dimethylglyoxime, which is widely used for the analytical determination of nickel.

Private representatives include hexamine nickel (II) chloride.

Hesaminnickel(II) chloride Cl2 is a light yellow or light blue hygroscopic powder that partially decomposes in air. Dissolves already in cold water. The thermal stability of the resulting complex ammonia is very high. Decomposes with water to release hydroxide

Ni:Cl2 =6H2O = Ni(OH)2 + 4NH4OH +2NH4Cl.

Oxygen has no effect on solutions of nickel ammonia

Nickel in this valency forms complexes with tetrahedral and planar square structures. For example, the tetrachloronicickelate(II)2− complex has a tetrahedral structure, while the tetracyanonickelate(II)2− complex has a planar square structure.

Nickel dimethylglyoxime/dimethylglyoximate.

The reaction of Ni 2+ ions with dimethylglyoxime (C4H8O2N2) is characteristic, leading to the formation of an intracomplex compound of pink-red nickel dimethylglyoximate, which is slightly soluble in water. Nickel dimethylglyoximate Ni(C 4 H 6 N 2 O 2) 2, a poorly soluble Ni(II) chelate complex in water, additionally stabilized by intramolecular hydrogen bonds, giving a clear red color in an acidic environment, is used in analytical chemistry as a qualitative reaction to Nickel(II) ions.

Nickel dimethylglyoximate Ni(C 4 H 6 N 2 O 2) 2 can be obtained by adding dimethylglyoxime (Chugaev's reagent) and ammonia water (ammonia) to a solution of Ni(II) salt.

Reaction equation: NiSO4 + 2C4H8O2N2+ 2NH3 => Ni(C4H7O2N2)2 + (NH4)2 SO4.

Nikel- malleable and ductile metal. Nickel is ferromagnetic. In air it is stable. There is a protective film of NiO on the surface, which protects the metal from further oxidation.

WITH H2O and water vapor contained in the air, nickel doesn't respond either. Nickel practically does not interact with such acids as sulfuric, phosphoric, hydrofluoric and some others.

Interacts with HNO3:

3Ni + 8HNO 3 = 3Ni(NO 3) 2 + 2NO + 4H 2 O

WITH O2 reacts only at temperatures above 800° C.

Nickel oxide has basic properties. It exists in 2 modifications: low temperature (hexagonal lattice) and high temperature (cubic lattice).

It reacts with halogens and sulfur only at temperature to form NiHal 2 and NiS. When interacting with C, P, the following are formed: carbide Ni3C, phosphides - Ni 5 P 2, Ni 2 P, Ni 3 P.

With non-metals ( N 2) the reaction proceeds under optimal conditions.

There are salts that are soluble in water NiSO 4 , Ni(NO 3) 2 and many others that form crystalline hydrates NiSO 4 7H 2 O, Ni(NO 3) 2 6H 2 O.

Insoluble salts: phosphate Ni 3 (PO 4) 2 and silicate Ni 2 SiO 4.

If you add alkali to a solution of nickel(II) salt, a green precipitate of nickel hydroxide will form:

Ni(NO 3) 2 + 2NaOH = Ni(OH) 2 + 2NaNO 3.

Ni(OH)2 has weakly basic properties. When interacting with alkali:

2Ni(OH) 2 + 2NaOH + Br 2 = 2Ni(OH) 3 + 2NaBr.

Application of nickel and its compounds.

Nickel is most widely used in the production of stainless steel and alloys. Alloys that consume a lot of nickel include:

Monel metal ( Ni, Cu, Fe, Mn), widely used in chemical equipment, shipbuilding, for the manufacture of settling tanks and covers;

Nichrome and chromel ( Ni, Cr), used in the form of wire for rheostats, toasters, irons, heaters;

Invar ( Ni, Fe), used due to its very low expansion coefficient for the manufacture of pendulums in watches and measuring tapes;

Permalloy ( Ni, Fe), used in marine cable and power transmission technology due to its excellent magnetic susceptibility;

Nickel silver ( Ni, Cu, Zn) - for the manufacture of household utensils;

Alnico ( Ni, Co, Fe, Al) is a powerful magnetic material used to make small tools that have the properties of a permanent magnet.

Nickel coatings have long been used for decorative purposes and to protect many base metals from corrosion, although they are often replaced by chrome plating.

Nickel sulfate is a crystalline substance of emerald green or turquoise color, soluble in water, eroded in air. This is a type of nickel salt.
Nickel sulfate is a highly toxic substance, so when working with it you must follow the rules for handling hazardous substances.
Chemical formula: NiSO4 7H2O.
Nickel sulfate is used in electroplating for nickel plating of products and metals.
And also - for the manufacture of batteries, catalysts, ferrites in the electronic and electrical industries, in metallurgy for the preparation of alloys. Nickel is widely used in the perfume, fat and chemical industries as a reagent.
In the production of ceramics, nickel sulfate is used as a dye.

Safety requirements for nickel sulfate (nickel sulfate heptahydrate, nickel sulfate) GOST 4465-74.
Nickel(II) sulfate 7-hydrate is a crystalline substance. When ingested into the human body, it has a carcinogenic and generally toxic effect. In contact with the skin and mucous membranes of the upper respiratory tract and eyes, the product is irritating and causes increased sensitivity to nickel.
When 7-aqueous nickel (II) sulfate is dissolved in water, a hydroaerosol is formed, which, according to the degree of impact on the body, belongs to substances of the 1st hazard class.
The maximum permissible concentration of hydroaerosol of 7-aqueous nickel sulfate in terms of nickel in the air of the working area is 0.005 mg/m³.
The maximum permissible concentration of nickel ion in the water of reservoirs for sanitary use is 0.1 mg/dm³.
7-hydrate nickel sulfate cannot be neutralized or destroyed. The spilled product after dry and subsequent wet cleaning is disposed of in technological processes for the production or consumption of nickel sulfate.
Nickel sulfate does not form toxic substances in the air and wastewater.
Nickel (II) sulfate 7-water is non-flammable, fire- and explosion-proof.
Everyone working with nickel sulfate must be provided with special clothing, special shoes and other protective equipment. To protect the respiratory system, the ShB-1 “Lepestok” respirator should be used. To avoid contact with the skin of the hands, it is recommended to use protective paste IER-2 and lanolin-castor ointment. If nickel sulfate gets into your eyes, rinse them with copious amounts of water.
Production and laboratory premises in which work with 7-aqueous nickel sulfate is carried out must be equipped with supply and exhaust ventilation, and the equipment must be sealed.

DEFINITION

Nickel- the twenty-eighth element of the Periodic Table. Designation - Ni from the Latin "niccolum". Located in the fourth period, VIIIB group. Refers to metals. The nuclear charge is 28.

Like cobalt, nickel occurs in nature primarily in the form of compounds with arsenic or sulfur; such, for example, are the minerals kupfernickel NiAs, arsenic-nickel luster NiAsS, etc. Nickel is more common than cobalt [about 0.01% (wt.) of the earth's crust].

Nickel metal has a silvery color with a yellowish tint (Fig. 1), is very hard, polishes well, and is attracted by a magnet. It is characterized by high corrosion resistance - stable in the atmosphere, in water, in alkalis and a number of acids. Actively dissolves in nitric acid. The chemical resistance of nickel is due to its tendency to passivation - to the formation of oxide films on the surface that have a strong protective effect.

Rice. 1. Nickel. Appearance.

Atomic and molecular mass of nickel

DEFINITION

Relative molecular mass of the substance (M r) is a number showing how many times the mass of a given molecule is greater than 1/12 the mass of a carbon atom, and relative atomic mass of an element (A r)— how many times the average mass of atoms of a chemical element is greater than 1/12 the mass of a carbon atom.

Since in the free state nickel exists in the form of monatomic Ni molecules, the values ​​of its atomic and molecular masses coincide. They are equal to 58.6934.

Nickel isotopes

It is known that in nature nickel can be found in the form of five stable isotopes 58 Ni, 60 Ni, 61 Ni, 62 Ni and 64 Ni. Their mass numbers are 58, 60, 61, 62 and 64, respectively. The nucleus of an atom of the nickel isotope 58 Ni contains twenty-eight protons and thirty neutrons, and the remaining isotopes differ from it only in the number of neutrons.

There are artificial unstable isotopes of nickel with mass numbers from 48 to 78, as well as eight meta-stable states, among which the longest-lived isotope 59 Ni with a half-life of 76 thousand years.

Nickel ions

The electronic formula demonstrating the orbital distribution of nickel electrons is as follows:

1s 2 2s 2 2p 6 3s 2 3p 6 3d 8 4s 2 .

As a result of chemical interaction, nickel gives up its valence electrons, i.e. is their donor, and turns into a positively charged ion:

Ni 0 -2e → Ni 2+ ;

Ni 0 -3e → Ni 3+ .

Nickel molecule and atom

In the free state, nickel exists in the form of monoatomic Ni molecules. Here are some properties characterizing the nickel atom and molecule:

Nickel alloys

The main mass of nickel is used for the production of various alloys with iron, copper, zinc and other metals. Adding nickel to steel increases its toughness and resistance to corrosion.

Nickel-based alloys can be divided into heat-resistant (nimonic, inconel, hastell [over 60% nickel, 15-20% chromium and other metals]), magnetic (permalloy) and alloys with special properties (monel metal, nickel, constantan, invar, platinite).

Examples of problem solving

EXAMPLE 1

Exercise Write the reaction equations that can be used to carry out the following transformations:

NiCl 2 → Ni → NiSO 4 → Ni(NO 3) 2 → Ni(OH) 2 → NiCl 2.

Draw the equations for reactions occurring in solutions in ionic and abbreviated ionic forms.
Answer By placing a metal more active than nickel in a solution of nickel (II) chloride, you can obtain nickel in free form (substitution reaction):

NiCl 2 + Zn → Ni + ZnCl 2;

Ni 2+ + Zn 0 → Ni 0 + Zn 2+ .

Nickel dissolves in dilute sulfuric acid to form nickel(II) sulfate:

Ni + H 2 SO 4 (dilute) → NiSO 4 + H 2;

Ni 0 + 2H + → Ni 2+ + H 2 .

Nickel(II) nitrate can be obtained by an exchange reaction:

NiSO 4 + Ba(NO 3) 2 → Ni(NO 3) 2 + BaSO 4 ↓;

SO 4 2- + Ba 2+ → BaSO 4 ↓.

By treating nickel (II) nitrate with alkali, you can obtain nickel (II) hydroxide:

Ni(NO 3) 2 + 2NaOH → Ni(OH) 2 ↓+ 2NaNO 3 ;

Ni 2+ + 2OH - = Ni(OH) 2 ↓.

Nickel(II) chloride from nickel(II) hydroxide can be obtained by neutralization reaction with hydrochloric acid:

Ni(OH) 2 + 2HCl → NiCl 2 + 2H 2 O;

OH - + H + = H 2 O.

EXAMPLE 2

Exercise What mass of nickel (II) chloride can be obtained by heating 17.7 g of nickel and 12 liters of chlorine (n.s.)? What volume of 0.06 M solution can be prepared from this mass of salt?
Solution Let's write the reaction equation:

Ni + Cl 2 = NiCl 2.

Let's find the number of moles of nickel (molar mass - 59 g/mol) and chlorine that reacted using the data specified in the problem statement:

n (Ni) = m (Ni) / M (Ni);

n(Ni) = 17.7 / 59 = 0.3 mol.

n (Cl 2) = V (Cl 2) / V m;

n (Cl 2) = 12 / 22.4 = 0.54 mol.

According to the equation of the problem n (Ni): n (Cl 2) = 1:1. This means that chlorine is in excess and all further calculations should be made using nickel. Let's find the amount of substance and the mass of nickel (II) chloride formed (molar mass 130 g/mol):

n (Ni): n (NiCl 2) = 1:1;

n (Ni) = n (NiCl 2) = 0.3 mol.

m (NiCl 2) = n (NiCl 2) × M (NiCl 2);

m (NiCl 2) = 0.3 × 130 = 39 g.

Let's calculate the volume of a 0.06 M solution that can be obtained from 39 g of nickel (II) chloride:

V(NiCl 2) = n (NiCl 2)/ c (NiCl 2);

V (NiCl 2) = 0.3 / 0.06 = 0.5 l.
Answer The mass of nickel (II) chloride is 39 g, the volume of a 0.06 M solution is 0.5 l (500 ml).

Section 1. Characteristics.

Section 2. Being in nature.

Section 3. Receipt.

Section 4. Application.

- Subsection 1. Alloys.

- Subsection 2. Nickel plating.

Section 5. Coinage.

Ni is an element of the side subgroup of the eighth group, the fourth period of the periodic table of chemical elements of D. I. Mendeleev, with atomic number 28.

Characteristics nickel

Ni- It is silvery white and does not fade in air. Has a face-centered cubic lattice with period a = 0.35238 NM, space group Fm3m. In its pure form it can be processed by pressure. It is ferromagnetic with a Curie point of 358 C.

Electrical resistivity 0.0684 μΩ∙m.

Coefficient of linear thermal expansion α=13.5∙10-6 K-1 at 0 C

Coefficient of volumetric thermal expansion β=38—39∙10-6 K-1

Elastic modulus 196-210 GPa.

Nickel atoms have an external electron configuration of 3d84s2. The most stable state for nickel is the oxidation state nickel(II).

Ni forms compounds with oxidation states +2 and +3. In this case, Ni with an oxidation state of +3 is only in the form of complex salts. A large number of ordinary and complex compounds are known for nickel +2 compounds. Nickel oxide Ni2O3 is a strong oxidizing agent.

Ni is characterized by high corrosion resistance - it is stable in air, water, alkalis, and a number of acids. Chemical resistance is due to its tendency to passivation - the formation of a dense oxide film on its surface, which has a protective effect. Ni is actively dissolved in nitric acid.

With carbon monoxide CO, Ni easily forms volatile and highly toxic nickel carbonite (CO)4.

Fine nickel powder is pyrophoric (self-ignites in air).

Ni burns only in powder form. It forms two oxides nickelO and Ni2O3 and, accordingly, two hydroxides nickel(OH)2 and nickel(OH)3. The most important soluble nickel salts are acetate, chloride, nitrate and sulfate.

Solutions are usually colored green, and anhydrous salts are yellow or brownish-yellow. Insoluble salts include oxalate and phosphate (green), three sulfides:

nickelS (black)

Ni3S2 (yellowish bronze)

Ni3S4 (silver-white).

Ni also forms numerous coordination and complex compounds.

Aqueous solutions of nickel(II) salts contain the hexaaquanickel(II) ion nickel(H2O)62+. When an ammonia solution is added to a solution containing these ions, nickel(II) hydroxide, a green, gelatinous substance, precipitates. This precipitate dissolves when excess ammonia is added due to the formation of hexamminnickel(II) ions, nickel(NH3)62+.

Ni forms complexes with tetrahedral and planar square structures. For example, the tetrachloronicickelate (II) NiCl42− complex has a tetrahedral structure, and the tetracyanonickelate (II) nickel(CN)42− complex has a planar square structure.

Qualitative and quantitative analysis uses an alkaline solution of butanedione dioxime, also known as dimethylglyoxime, to detect nickel(II) ions. When it reacts with nickel(II) ions, the red coordination compound bis(butanedionedioximato)Ni(II) is formed. This chelate compound and butanedione dioximate ligand is bidentate.

Natural Ni consists of 5 stable isotopes, 58 nickel, 60 nickel, 61 nickel, 62 nickel is the most abundant (68.077% of natural abundance).

Being in nature

Ni is quite common in nature - its content in the earth's crust is about 0.01% (mass). In the earth's crust it is found only in bound form; iron meteorites contain native Ni (up to 8%). Its content in ultramafic rocks is approximately 200 times higher than in acidic rocks (1.2 kg/t and 8 g/t). In ultramafic rocks, the predominant amount of nickel is associated with olivines containing 0.13 - 0.41% nickel. It isomorphically replaces magnesium.

A small portion of nickel is present in the form of sulfides. Ni exhibits siderophilic and chalcophilic properties. With an increased content of sulfur in the magma, nickel sulfides appear along with copper, cobalt, iron and platinoids. In the hydrothermal process, together with cobalt, arsenic and gray and sometimes with bismuth, uranium and silver, Ni forms increased concentrations in the form of nickel arsenides and sulfides. Ni is commonly found in sulfide and arsenic-bearing copper-nickel ores.

Nickelin (red nickel pyrite, cupfernickel) nickel As.

Chloantite (white nickel pyrite) (Nickel, Co, Fe)As2

Garnierite (Mg, nickel)6(Si4O11)(OH)6 with H2O and other silicates.

Magnetic pyrite (Fe, nickel, Cu)S

Arsenic-nickel luster (gersdorffite) nickel As S,

Pentlandite (Fe, nickel)9S8

Much is already known about nickel in organisms. It has been established, for example, that its content in human blood changes with age, that in animals the amount of nickel in the body is increased, and finally, that there are some plants and microorganisms - “concentrators” of nickel, containing thousands and even hundreds of thousands of times more nickel than environment.

Receipt

The total reserves of nickel in ores at the beginning of 1998 are estimated at 135 million tons, including reliable reserves of 49 million tons. The main nickel ores are nickel (kupfernickel) nickel As, millerite nickel S, pentlandite (Fe nickel)9S8 - also contain arsenic, iron And sulfur; igneous pyrrhotite also contains pentlandite inclusions. Other ores from which nickel is also mined contain Co impurities, Cu, Fe and Mg. Sometimes Ni is the main product process refining, but more often it is obtained as a by-product product in technologies of other metals. Of the reliable reserves, according to various sources, from 40 to 66% of nickel is in oxidized nickel ores (OHN),

33% in sulfide. As of 1997, the share of nickel produced by OHP processing was about 40% of global production. In industrial conditions, OHP is divided into two types: magnesium and ferruginous.

Refractory magnesium ores, as a rule, are subjected to electric smelting using ferronickel (5-50% nickel + Co, depending on the composition of the raw material and technological features).

The most ferrous - laterite ores are processed by hydrometallurgical methods using ammonia-carbonate leaching or sulfuric acid autoclave leaching. Depending on the composition of the raw materials and the applied technological schemes, the final products of these technologies are: nickel oxide (76-90% nickel), sinter (89% nickel), sulfide concentrates of various compositions, as well as metallic Ni electrolyte, nickel powders and cobalt.

Less ferrous nontronite ores are smelted into matte. At full-cycle enterprises, the further processing scheme includes conversion, matte firing, and electric smelting of nickel oxide to produce metallic nickel. Along the way, the recovered cobalt is released in the form of metal and/or salts. Another source of nickel: in the coal ash of South Wales in Britain - up to 78 kg of nickel per ton. The increased nickel content in some coals, oils, and shale indicates the possibility of nickel concentration in fossil organic matter. The reasons for this phenomenon have not yet been clarified.

“Ni could not be obtained in plastic form for a long time due to the fact that it always contains a small admixture of sulfur in the form of nickel sulfide, located in thin, fragile layers at the boundaries metal. Adding a small amount of magnesium to molten nickel converts the sulfur into the form of a compound with magnesium, which is released in the form of grains without affecting the plasticity metal».

The bulk of nickel is obtained from garnierite and magnetic pyrite.

Silicate ore is reduced with coal dust in rotary tube kilns to iron-nickel pellets (5-8% nickel), which are then cleaned of sulfur, calcined and treated with an ammonia solution. After acidifying the solution, metal is obtained from it electrolytically.

Carbonyl method (Mond method). First, copper-nickel matte is obtained from sulfide ore, over which cobalt is passed under high pressure. Highly volatile tetracarbonylnickel nickel(CO)4 is formed, and thermal decomposition produces a particularly pure metal.

Aluminothermic method for the recovery of nickel from oxide ore: 3NiO + 2Al = 3Ni +Al2O.

Application

Alloys

Ni is the basis of most super alloys - heat-resistant materials used in the aerospace industry for power plant parts.

monel metal (65 - 67% nickel + 30 - 32% Cu+ 1% Mn), heat resistant up to 500°C, very corrosion resistant;

white (585 contains 58.5% gold and an alloy (ligature) of silver and nickel (or palladium));

Nichrome, resistance alloy (60% nickel + 40% Cr);

Permalloy (76% nickel + 17% Fe + 5% Cu + 2% Cr), has high magnetic susceptibility with very low hysteresis losses;

Invar (65% Fe + 35% nickel), almost does not elongate when heated;

In addition, nickel alloys include nickel and chromium-nickel steels, nickel silver and various resistance alloys such as constantan, nickel and manganin.

Nickel pipes are used for the manufacture of capacitors in hydrogen production and for pumping alkalis in chemical production. Chemically resistant nickel instruments are widely used in medicine and scientific research. Ni is used for radar, television, remote control devices processes in nuclear engineering.

Chemical utensils, various apparatus, instruments, boilers with high corrosion resistance and constancy of physical properties are made from pure nickel, and reservoirs and cisterns are made from nickel materials for storing food products, chemical reagents, essential oils, for transporting alkalis, for melting caustic alkalis.

Based on pure nickel powders, porous filters are made for filtering gases, fuels and other products in the chemical industry. industry. Powdered Ni is also used in the production of nickel alloys and as a binder in the manufacture of hard and superhard materials.

The biological role of nickel is one of the microelements necessary for the normal development of living organisms. However, little is known about its role in living organisms. It is known that Ni takes part in enzymatic reactions in animals and plants. In animals, it accumulates in keratinized tissues, especially feathers. Increased nickel content in soils leads to endemic diseases - ugly forms appear in plants, and eye diseases in animals associated with the accumulation of nickel in the cornea. Toxic dose (for rats) - 50 mg. Volatile nickel compounds are especially harmful, in particular its tetracarbonyl nickel (CO)4. The maximum permissible concentration for nickel compounds in air ranges from 0.0002 to 0.001 mg/m3 (for various compounds).

Ni is the main cause of allergies (contact dermatitis) to metals that come into contact with the skin (jewelry, watches, denim rivets).

The European Union limits the nickel content in products that come into contact with human skin.

Nickel carbonite nickel (CO) is very poisonous. The maximum permissible concentration of its vapors in the air of industrial premises is 0.0005 mg/m3.

In the 20th century, it was found that the pancreas is very rich in nickel. When nickel is administered after insulin, the action of insulin is prolonged and thus hypoglycemic activity increases. Ni affects enzymatic processes, the oxidation of ascorbic acid, and accelerates the transition of sulfhydryl groups to disulfide groups. Ni may inhibit the action of adrenaline and lower blood pressure. Excessive intake of nickel into the body causes vitiligo. Ni is deposited in the pancreas and parathyroid glands.

Nickel plating

Nickel plating is the creation of a nickel coating on the surface of another metal to protect it from corrosion. It is carried out by electroplating using electrolytes containing nickel(II) sulfate, sodium chloride, boron hydroxide, surfactants and gloss agents, and soluble nickel anodes. The thickness of the resulting nickel layer is 12 - 36 microns. Stable surface gloss can be ensured by subsequent chrome plating (chrome layer thickness 0.3 microns).

Nickel plating without current is carried out in a solution of a mixture of nickel(II) chloride and a sodium hypophosphite mixture in the presence of sodium citrate:

NiCl2 + NaH2PO2 + H2O = nickel + NaH2PO3 + 2HCl

the process is carried out at pH 4 - 6 and 95°C

The most common are electrolytic and chemical nickel plating. More often, nickel plating (the so-called matte) is done electrolytically. The most studied and stable in work sulfuric acid electrolytes. When brightening agents are added to the electrolyte, so-called bright nickel plating is carried out. Electrolytic coatings have some porosity, which depends on the thorough preparation of the substrate surface and the thickness of the coating. To protect against corrosion, a complete absence of pores is necessary, so a multilayer coating is applied, which, with equal thickness, is more reliable than a single layer (for example, steel item of trade often plated according to the Cu - Nickel - Cr scheme).

The disadvantages of electrolytic nickel plating are the uneven deposition of nickel on a relief surface and the impossibility of coating narrow and deep holes, cavities, etc. Chemical nickel plating is somewhat more expensive than electrolytic plating, but it provides the possibility of applying a coating of uniform thickness and quality on any areas of the relief surface, provided the solution has access to them. The process is based on the reduction reaction of nickel ions from its salts using a sodium hypophosphite mixture (or other reducing agents) in aqueous solutions.

Nickel plating is used, for example, to coat parts of chemical equipment, cars, bicycles, medical instruments, and devices.

Ni is also used to produce winding strings for musical instruments.

Coinage

Ni is widely used in coin production in many countries. In the United States, the 5-cent coin is colloquially known as "Ni"

Ni has been a component of coins since the mid-19th century. In the United States, the term "Ni" or "nickel" was originally applied to the cuprum coins (flying eagle), which replaced the cuprum with 12% nickel in 1857-58.

Still later in 1865, the term assigned to three percent nickel increased by 25%. In 1866 five percent nickel (25% nickel, 75% cuprum). Along with proportion alloy, this term has been used currently in the United States. Near-pure nickel coins were first used in 1881 in Switzerland, and notably more than 99.9% Ni of five-cent coins were minted in Canada (the largest nickel producer in the world at the time).

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Sources

Wikipedia - The Free Encyclopedia, WikiPedia

hyperon-perm.ru - Production Hyperon

cniga.com.ua - Book portal

chem100.ru - Chemist's Directory

bse.sci-lib.com - The meaning of words in the Great Soviet Encyclopedia

chemistry.narod.ru - World of Chemistry

dic.academic.ru - Dictionaries and encyclopedias


Investor Encyclopedia. 2013 .

Synonyms:
  • Nicaragua

See what "Nickel" is in other dictionaries:

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    NICKEL Historical Dictionary of Gallicisms of the Russian Language - (lat. Niccolum) Ni, chemical element of group VIII of the periodic system, atomic number 28, atomic mass 58.69. The name is from the German Nickel, the name of an evil spirit that allegedly interfered with the miners. Silver-white metal; density 8.90 g/cm³, melting point 1455… …

    NICKEL Big Encyclopedic Dictionary - NICKEL, nickel, husband. (German Nickel). Silver-white refractory metal, used. for making tools, utensils, etc. (By the name of a mountain deity in Scandinavian mythology.) Ushakov’s explanatory dictionary. D.N. Ushakov. 1935 1940 …


See what “Nickel” is in other dictionaries Use of nickel and its compounds