Names | |
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Other names Nickel(II) tungstate Nickel tungsten oxide | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.034.560 |
EC Number |
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PubChem CID | |
CompTox Dashboard (EPA) | |
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Properties | |
NiWO4 | |
Molar mass | 306.534 |
Appearance | green crystals [1] |
Odor | odourless [1] [2] |
Density | 3.3723 g/cm³ [3] |
Melting point | 1420 ˚C [4] |
insoluble [2] | |
Solubility | soluble in ammonia |
Structure | |
monoclinic crystal system | |
Hazards | |
GHS labelling: | |
Danger | |
H317, H350i, H372 | |
P201, P260, P280, P308+P313, P405, P501 | |
Related compounds | |
Other anions | Nickel(II) chromate Nickel(II) molybdate |
Other cations | Iron(II) tungstate Cobalt(II) tungstate Zinc(II) tungstate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Nickel tungstate is an inorganic compound of nickel, tungsten and oxygen, with the chemical formula of NiWO4.
Nickel tungstate can be prepared by the reaction of nickel(II) nitrate and sodium tungstate: [5]
Nickel tungstate can also be prepared by the reaction of nickel(II) oxide and tungsten(VI) oxide. [6]
It can also be obtained by the reaction of ammonium metatungstate and nickel(II) nitrate [7] or from the reaction of sodium tungstate, nickel(II) chloride and sodium chloride. [8]
Nickel tungstate undergoes a phase transition at 700°C. [5]
Nickel tungstate is a light brown, odourless solid that is insoluble in water. [2] The amorphous form is green and the polycrystalline form is brown. [5] It crystallizes in the wolframite crystal structure of the monoclinic crystal system with space group P2/c (No. 13). [9] [8] The compound is antiferromagnetic. [10] [11]
Nickel tungstate has no commercial uses. It has been examined as a photocatalyst, in humidity sensors, and in dielectric resonators. It is also considered as a "promising" cathode material for asymmetric supercapacitors. [1] [12]
Nickel tungstate forms compounds with ammonia, such as NiWO4·2NH3·H2O which are cyan crystals, [13] NiWO4·4NH3 which are green crystals, [14] NiWO4·5NH3·H2O as dark blue crystals [13] or anhydrous NiWO4·6NH3 which is crystalline purple, while the octahydrate of hexamine is dark blue. [14]
Copper(II) nitrate describes any member of the family of inorganic compounds with the formula Cu(NO3)2(H2O)x. The hydrates are blue solids. Anhydrous copper nitrate forms blue-green crystals and sublimes in a vacuum at 150-200 °C. Common hydrates are the hemipentahydrate and trihydrate.
In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions. In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.
Tungsten(VI) oxide, also known as tungsten trioxide is a chemical compound of oxygen and the transition metal tungsten, with formula WO3. The compound is also called tungstic anhydride, reflecting its relation to tungstic acid H2WO4. It is a light yellow crystalline solid.
Sodium tungstate is the inorganic compound with the formula Na2WO4. This white, water-soluble solid is the sodium salt of tungstic acid. It is useful as a source of tungsten for chemical synthesis. It is an intermediate in the conversion of tungsten ores to the metal.
Zinc nitrate is an inorganic chemical compound with the formula Zn(NO3)2. This colorless, crystalline salt is highly deliquescent. It is typically encountered as a hexahydrate Zn(NO3)2·6H2O. It is soluble in both water and alcohol.
Iron(III) nitrate, or ferric nitrate, is the name used for a series of inorganic compounds with the formula Fe(NO3)3.(H2O)n. Most common is the nonahydrate Fe(NO3)3.(H2O)9. The hydrates are all pale colored, water-soluble paramagnetic salts.
Nickel nitrate is the inorganic compound Ni(NO3)2 or any hydrate thereof. In the hexahydrate, the nitrate anions are not bonded to nickel. Other hydrates have also been reported: Ni(NO3)2.9H2O, Ni(NO3)2.4H2O, and Ni(NO3)2.2H2O.
Cadmium hydroxide is an inorganic compound with the formula Cd(OH)2. It is a white crystalline ionic compound that is a key component of nickel–cadmium battery.
Manganese(II) nitrate refers to the inorganic compounds with formula Mn(NO3)2·(H2O)n. These compounds are nitrate salts containing varying amounts of water. A common derivative is the tetrahydrate, Mn(NO3)2·4H2O, but mono- and hexahydrates are also known as well as the anhydrous compound. Some of these compounds are useful precursors to the oxides of manganese. Typical of a manganese(II) compound, it is a paramagnetic pale pink solid.
Barium tungstate is an inorganic chemical compound of barium and the tungstate anion.
Nickel is one of the metals that can form Tutton's salts. The singly charged ion can be any of the full range of potassium, rubidium, cesium, ammonium (), or thallium. As a mineral the ammonium nickel salt, (NH4)2Ni(SO4)2 · 6 H2O, can be called nickelboussingaultite. With sodium, the double sulfate is nickelblödite Na2Ni(SO4)2 · 4 H2O from the blödite family. Nickel can be substituted by other divalent metals of similar sized to make mixtures that crystallise in the same form.
The Nickel oxyacid salts are a class of chemical compounds of nickel with an oxyacid. The compounds include a number of minerals and industrially important nickel compounds.
Indium(III) nitrate is a nitrate salt of indium which forms various hydrates. Only the pentahydrate has been crystallographically verified. Other hydrates are also reported in literature, such as the trihydrate.
Iron(II) nitrate is the nitrate salt of iron(II). It is commonly encountered as the green hexahydrate, Fe(NO3)2·6H2O, which is a metal aquo complex, however it is not commercially available unlike iron(III) nitrate due to its instability to air. The salt is soluble in water and serves as a ready source of ferrous ions.
A transition metal nitrate complex is a coordination compound containing one or more nitrate ligands. Such complexes are common starting reagents for the preparation of other compounds.
Praseodymium compounds are compounds formed by the lanthanide metal praseodymium (Pr). In these compounds, praseodymium generally exhibits the +3 oxidation state, such as PrCl3, Pr(NO3)3 and Pr(CH3COO)3. However, compounds with praseodymium in the +2 and +4 oxidation states, and unlike other lanthanides, the +5 oxidation state, are also known.
Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod.
Cobalt compounds are chemical compounds formed by cobalt with other elements.
Neodymium tungstate is an inorganic compound, a salt of neodymium and tungstic acid with the chemical formula Nd2(WO4)3. It forms hydrated light purple crystals that are slightly soluble in water.
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