Ammonium dimolybdate

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Ammonium dimolybdate
Names
Other names
ADM
Identifiers
3D model (JSmol)
ECHA InfoCard 100.044.092 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
  • InChI=1S/2Mo.H3N.8O/h;;1H3;;;;;;;;/q;;;;;;;4*-1/p+1
    Key: UHQWHVHZVHVJFE-UHFFFAOYSA-O
  • [NH4+].[O-][Mo](=O)(=O)O[Mo](=O)(=O)[O-].[NH4+]
Properties
H8N2Mo2O7
Appearancewhite solid
Density 2.97 g/cm3
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Ammonium dimolybdate (ADM) is the inorganic compound with the formula (NH4)2Mo2O7. It is a white, water-soluble solid. ADM is an intermediate in the production of molybdenum compounds from its ores. Roasting typical ore produces crude molybdenum(VI) oxides, which can be extracted into aqueous ammonia, affording ammonium molybdate. Heating solutions of ammonium molybdate gives ADM. Upon heating, solid ammonium dimolybdate decomposes to molybdenum trioxide: [1]

(NH4)2Mo2O7 → 2 MoO3 + 2 NH3 + H2O

In terms of its chemical structure, the anion is a polymeric consisting of distorted octahedral Mo centers liked by tetrahedral molybdate centers. [2] When prepared in the absence of water as its tetrabutylammonium salt, dimolybdate adopts the centrosymmetric structure observed for dichromate. [3]

Related Research Articles

<span class="mw-page-title-main">Molybdenum</span> Chemical element, symbol Mo and atomic number 42

Molybdenum is a chemical element; it has symbol Mo and atomic number 42. The name derived from Ancient Greek Μόλυβδος molybdos, meaning lead, since its ores were confused with lead ores. Molybdenum minerals have been known throughout history, but the element was discovered in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm.

<span class="mw-page-title-main">Oxide</span> Chemical compound where oxygen atoms are combined with atoms of other elements

An oxide is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– ion with oxygen in the oxidation state of −2. Most of the Earth's crust consists of oxides. Even materials considered pure elements often develop an oxide coating. For example, aluminium foil develops a thin skin of Al2O3 that protects the foil from further oxidation.

<span class="mw-page-title-main">Group 7 element</span> Group of chemical elements

Group 7, numbered by IUPAC nomenclature, is a group of elements in the periodic table. It contains manganese (Mn), technetium (Tc), rhenium (Re) and bohrium (Bh). This group lies in the d-block of the periodic table, and are hence transition metals. This group is sometimes called the manganese group or manganese family after its lightest member; however, the group itself has not acquired a trivial name because it belongs to the broader grouping of the transition metals.

<span class="mw-page-title-main">Polyoxometalate</span> Ion with many transition metals

In chemistry, a polyoxometalate is a polyatomic ion, usually an anion, that consists of three or more transition metal oxyanions linked together by shared oxygen atoms to form closed 3-dimensional frameworks. The metal atoms are usually group 6 or less commonly group 5 and group 7 transition metals in their high oxidation states. Polyoxometalates are often colorless, orange or red diamagnetic anions. Two broad families are recognized, isopolymetalates, composed of only one kind of metal and oxide, and heteropolymetalates, composed of one or more metals, oxide, and eventually a main group oxyanion. Many exceptions to these general statements exist.

Molybdenum trioxide describes a family of inorganic compounds with the formula MoO3(H2O)n where n = 0, 1, 2. The anhydrous compound is produced on the largest scale of any molybdenum compound since it is the main intermediate produced when molybdenum ores are purified. The anhydrous oxide is a precursor to molybdenum metal, an important alloying agent. It is also an important industrial catalyst. It is a yellow solid, although impure samples can appear blue or green.

<span class="mw-page-title-main">Ammonium persulfate</span> Chemical compound

Ammonium persulfate (APS) is the inorganic compound with the formula (NH4)2S2O8. It is a colourless (white) salt that is highly soluble in water, much more so than the related potassium salt. It is a strong oxidizing agent that is used as a catalyst in polymer chemistry, as an etchant, and as a cleaning and bleaching agent.

<span class="mw-page-title-main">Sodium molybdate</span> Chemical compound

Sodium molybdate, Na2MoO4, is useful as a source of molybdenum. This white, crystalline salt is often encountered as the dihydrate, Na2MoO4·2H2O.

Indium(III) sulfate (In2(SO4)3) is a sulfate salt of the metal indium. It is a sesquisulfate, meaning that the sulfate group occurs 11/2 times as much as the metal. It may be formed by the reaction of indium, its oxide, or its carbonate with sulfuric acid. An excess of strong acid is required, otherwise insoluble basic salts are formed. As a solid indium sulfate can be anhydrous, or take the form of a pentahydrate with five water molecules or a nonahydrate with nine molecules of water. Indium sulfate is used in the production of indium or indium containing substances. Indium sulfate also can be found in basic salts, acidic salts or double salts including indium alum.

<span class="mw-page-title-main">Ammonium hexachloroplatinate</span> Chemical compound

Ammonium hexachloroplatinate, also known as ammonium chloroplatinate, is the inorganic compound with the formula (NH4)2[PtCl6]. It is a rare example of a soluble platinum(IV) salt that is not hygroscopic. It forms intensely yellow solutions in water. In the presence of 1M NH4Cl, its solubility is only 0.0028 g/100 mL.

<span class="mw-page-title-main">Ammonium tetrathiomolybdate</span> Chemical compound

Ammonium tetrathiomolybdate is the chemical compound with the formula (NH4)2MoS4. This bright red ammonium salt is an important reagent in the chemistry of molybdenum and has been used as a building block in bioinorganic chemistry. The thiometallate (see metallate) anion has the distinctive property of undergoing oxidation at the sulfur centers concomitant with reduction of the metal from Mo(VI) to Mo(IV).

<span class="mw-page-title-main">Ammonium paratungstate</span> Chemical compound

Ammonium paratungstate (or APT) is a white crystalline salt with the chemical formula (NH4)10(H2W12O42)·4H2O. It is described as "the most important raw material for all other tungsten products."

<span class="mw-page-title-main">Ammonium heptamolybdate</span> Chemical compound

Ammonium heptamolybdate is the inorganic compound whose chemical formula is (NH4)6Mo7O24, normally encountered as the tetrahydrate. A dihydrate is also known. It is a colorless solid, often referred to as ammonium paramolybdate or simply as ammonium molybdate, although "ammonium molybdate" can also refer to ammonium orthomolybdate, (NH4)2MoO4, and several other compounds. It is one of the more common molybdenum compounds.

<span class="mw-page-title-main">Molybdenum blue</span> Pigment

Molybdenum blue is a term applied to:

Aluminium molybdate is the chemical compound Al2(MoO4)3. It forms in certain hydrodesulfurization catalysts when alumina is doped with excess molybdenum. When molybdates are used to inhibit corrosion in aluminum piping, the protective film formed is hydrated aluminum molybdate. Although small quantities of aluminum molybdate form during aluminothermic reduction of molybdia, mechanical activation inhibits their formation.

<span class="mw-page-title-main">Molybdate</span> Chemical compound of the form –O–MoO₂–O–

In chemistry, a molybdate is a compound containing an oxyanion with molybdenum in its highest oxidation state of 6: O−Mo(=O)2−O. Molybdenum can form a very large range of such oxyanions, which can be discrete structures or polymeric extended structures, although the latter are only found in the solid state. The larger oxyanions are members of group of compounds termed polyoxometalates, and because they contain only one type of metal atom are often called isopolymetalates. The discrete molybdenum oxyanions range in size from the simplest MoO2−
4
, found in potassium molybdate up to extremely large structures found in isopoly-molybdenum blues that contain for example 154 Mo atoms. The behaviour of molybdenum is different from the other elements in group 6. Chromium only forms the chromates, CrO2−
4
, Cr
2
O2−
7
, Cr
3
O2−
10
and Cr
4
O2−
13
ions which are all based on tetrahedral chromium. Tungsten is similar to molybdenum and forms many tungstates containing 6 coordinate tungsten.

Ammonium orthomolybdate is the inorganic compound with the chemical formula (NH4)2MoO4. It is a white solid that is prepared by treating molybdenum trioxide with aqueous ammonia. Upon heating these solutions, ammonia is lost, to give ammonium heptamolybdate ((NH4)6Mo7O24·4H2O).

<span class="mw-page-title-main">Manganese(II) molybdate</span> Inorganic compound

Manganese(II) molybdate is an inorganic compound with the chemical formula MnMoO4. α-MnMoO4 has a monoclinic crystal structure. It is also antiferromagnetic at low temperatures.

Scandium bromide, or ScBr3, is a trihalide, hygroscopic, water-soluble chemical compound of scandium and bromine.

Neodymium molybdate is an inorganic compound, with the chemical formula of Nd2(MoO4)3.

<span class="mw-page-title-main">Molybdenum difluoride dioxide</span> Chemical compound

Molybdenum difluoride dioxide is the inorganic compound with the formula MoF2O2. It is a white, diamagnetic, volatile solid.

References

  1. Roger F. Sebenik; et al. (2005). "Molybdenum and Molybdenum Compounds". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a16_655. ISBN   3527306730. S2CID   98762721.
  2. Armour, A. W.; Drew, M. G. B.; Mitchell, P. C. H. "Crystal and molecular structure and properties of ammonium dimolybdate" Journal of the Chemical Society, Dalton Transactions,1975, p1493-p1496. {{DOI: 10.1039/DT9750001493}}
  3. Day, V. W.; Klemperer, W. G. (1985). "Metal Oxide Chemistry in Solution: The Early Transition Metal Polyoxoanions". Science. 228 (4699): 533–541. Bibcode:1985Sci...228..533D. doi:10.1126/science.228.4699.533. PMID   17736064. S2CID   32953306.