World Library  
Flag as Inappropriate
Email this Article

Sodium molybdate

Article Id: WHEBN0002845369
Reproduction Date:

Title: Sodium molybdate  
Author: World Heritage Encyclopedia
Language: English
Subject: Sodium chromate, Molybdate, Molybdates, Metal aromaticity, Dietary minerals
Collection: Dietary Minerals, Inorganic Compounds, Molybdates, Sodium Compounds
Publisher: World Heritage Encyclopedia

Sodium molybdate

Sodium molybdate
Sodium molybdate
IUPAC name
Sodium molybdate
Other names
Disodium molybdate
(dihydrate) N
ChemSpider  N
EC number 231-551-7
Jmol-3D images Image
RTECS number QA5075000
Molar mass 205.92 g/mol (anhydrous)
241.95 g/mol (dihydrate)
Appearance White powder
Density 3.78 g/cm3, solid
Melting point 687 °C (1,269 °F; 960 K)
84 g/100 ml (100 °C)
Safety data sheet External MSDS
NFPA 704
Flash point Non-flammable
Lethal dose or concentration (LD, LC):
LD50 (Median dose)
4000 mg/kg (rat, oral)[1]
>2080 mg/m3 (rat, 4 hr)[1]
Related compounds
Other anions
Sodium chromate
Sodium tungstate
Other cations
Ammonium molybdate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 N  (: Y/N?)

Sodium molybdate, Na2MoO4, is useful as a source of molybdenum.[2] It is often found as the dihydrate, Na2MoO4·2H2O.

The molybdate(VI) anion is tetrahedral. Two sodium cations coordinate with every one anion.[3]


  • History 1
  • Uses 2
  • Reactions 3
  • Safety 4
  • References 5
  • External links 6


Sodium molybdate was first synthesized by the method of hydration.[4] A more convenient synthesis is done by dissolving MoO3 in sodium hydroxide at 50–70 °C and crystallizing the filtered product.[3] The anhydrous salt is prepared by heating to 100 °C.

MoO3 + 2NaOH + H2O → Na2MoO4·2H2O


The agriculture industry uses 1 million pounds per year as a fertilizer. In particular, its use has been suggested for treatment of whiptail in broccoli and cauliflower in molybdenum-deficient soils.[5][6] However, care must be taken because at a level of 0.3 ppm sodium molybdate can cause copper deficiencies in animals, particularly cattle.[3]

It is used in industry for corrosion inhibition, as it is a non-oxidizing anodic inhibitor.[3] The addition of sodium molybdate significantly reduces the nitrite requirement of fluids inhibited with nitrite-amine, and improves the corrosion protection of carboxylate salt fluids.[7]

In industrial water treatment applications where galvanic corrosion is a potential due to bimetallic construction, the application of sodium molybdate is preferred over sodium nitrite. Sodium molybdate has the advantage in that the dosing of lower ppm's of molybdate allow for lower conductivity of the circulating water. Sodium molybdate at levels of 50-100 ppm offer the same levels of corrosion inhibition that sodium nitrite at levels of 800+ ppm. By utilizing lower concentrations of sodium molybdate, conductivity is kept at a minimum and thus galvanic corrosion potentials are decreased.[8]


When reacted with sodium borohydride, molybdenum is reduced to a lower valent oxide:[9]

Na2MoO4 + NaBH4 + 2H2O→ NaBO2 + MoO2 + 2NaOH+ 3 H2

Sodium molybdate reacts with the acids of dithiophosphates:[3]

Na2MoO4 + (RO)2PS2H (R = Me, Et) → [MoO2(S2P(OR)2)2]

which further reacts to form [MoO3(S2P(OR)2)4].


Sodium molybdate is incompatible with alkali metals, most common metals and oxidizing agents. It will explode on contact with molten magnesium. It will violently react with interhalogens (e.g., bromine pentafluoride; chlorine trifluoride). Its reaction with hot sodium, potassium or lithium is incandescent.[10]


  1. ^ a b "Molybdenum (soluble compounds, as Mo)". Immediately Dangerous to Life and Health.  
  2. ^  
  3. ^ a b c d e Braithwaite, E.R.; Haber, J. Molybdenum: An outline of its Chemistry and Uses. 1994. Elsevier Science B.V. Amsterdam, The Netherlands.
  4. ^ Spitsyn, Vikt. I.; Kuleshov, I. M. Zhurnal Obshchei Khimii 1951. 21. 1701-15.
  5. ^ Plant, W. (1950). "Use of Lime and Sodium Molybdate for the Control of ‘Whiptail’ in Broccoli". Nature 165 (4196): 533.  
  6. ^ Davies, E. B. (1945). "A Case of Molybdenum Deficiency in New Zealand". Nature 156 (3961): 392.  
  7. ^ Vukasovich, Mark S. Lubrication Engineering 1980. 36(12). 708-12.
  8. ^ M. Houser, Corrosion Control Services, Inc., Introduction Handbook
  9. ^ Chi Fo Tsang and Arumugam Manthiram. Journal of Materials Chemistry 1997. 7(6). 1003–1006.
  10. ^

External links

  • Linus Pauling Institute page on molybdenum.
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Hawaii eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.