Ammonium orthomolybdate

In this article, we will explore the importance of Ammonium orthomolybdate in today's society. From its relevance in history to its impact on the modern world, Ammonium orthomolybdate has been a topic of constant interest for academics, experts, and everyday people alike. Through a detailed and exhaustive analysis, we will examine the various facets of Ammonium orthomolybdate and its influence on different aspects of society, culture and everyday life. Additionally, we will address the controversies and debates that have surrounded Ammonium orthomolybdate, as well as its evolution over time. This article aims to provide a complete and balanced view of Ammonium orthomolybdate, in order to deepen its understanding and appreciation in the current context.

Ammonium orthomolybdate
Names
Other names
Diammonium molybdate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.032.741 Edit this at Wikidata
EC Number
  • 236-031-3
  • InChI=1S/Mo.2H3N.4O/h;2*1H3;;;;/q;;;;;2*-1/p+2
    Key: APUPEJJSWDHEBO-UHFFFAOYSA-P
  • .O=()()=O.
Properties
(NH4)2MoO4
Molar mass 196.02 g/mol
Appearance colorless monoclinic crystals
Density 2.276 g/cm3
Melting point decomposes upon heating
soluble
Solubility insoluble in alcohol and liquid ammonia
Hazards
Lethal dose or concentration (LD, LC):
1870 mg/kg (rabbit, oral)
2200 mg/kg (guinea pig, oral)
1600 mg/kg (cat, oral)[1]
120 mg Mo/kg (rat, oral)
120 mg Mo/kg (guinea pig, oral)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).

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).

Uses

Ammonium orthomolybdate is used as a corrosion inhibitor and is an intermediate in some schemes to win molybdenum from its ores.[2] It is also used for decorating ceramics, and for colorimetric analysis of phosphates and arsenates.

Chemical reactions

Heating ammonium orthomolybdate solid or treatment with acid gives molybdenum trioxide. Such reactions proceed via ammonium dimolybdate. This equilibrium is exploited in the purification of molybdenum from its ores. Aqueous solutions of ammonium orthomolybdate react with hydrogen sulfide to give ammonium tetrathiomolybdate:

(NH4)2MoO4 + 4 H2S → (NH4)2MoS4 + 4 H2O

It reacts with arsenic acid upon heating to form a canary yellow precipitate of ammonium α-Keggin molybdoarsenate.

(NH4)2MoO4 + H3AsO4 → (NH4)2 + 21 NH4NO3 + 12 H2O[3]

References

  1. ^ a b "Molybdenum (soluble compounds, as Mo)". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  2. ^ Roger F. Sebenik et al. "Molybdenum and Molybdenum Compounds" in Ullmann's Encyclopedia of Chemical Technology 2005; Wiley-VCH, Weinheim. doi:10.1002/14356007.a16_655
  3. ^ Murakami, Masahiko; Hirano, Masaya; Shibahara, Toshiaki; Kubota, Toshio (18 February 2016). "Speciation of Inorganic Arsenic in Groundwater as Molybdoarsenate by On-Site Solid-Phase Extraction and Graphite Furnace Atomic Absorption Spectrometry". Analytical Letters. 49 (13): 2119–2131. doi:10.1080/00032719.2015.1135932. S2CID 100305249.