Sodium chromate

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Sodium chromate
Chroman sodný.JPG
CAS number 7775-11-3 YesY
PubChem 24488
EC number 231-889-5
UN number 3288
RTECS number GB2955000
Jmol-3D images Image 1
Molecular formula Na2CrO4
Molar mass 161.97 g/mol
Appearance yellow crystals
Odor odorless
Density 2.698 g/cm3
Melting point 792 °C (anhydrous)
20 °C (decahydrate)
Solubility in water 31.8 g/100 mL (0 °C)
84.5 g/100 mL (25 °C)
126.7 g/100 mL (100 °C)
Solubility slightly soluble in ethanol
Solubility in methanol 0.344 g/100 mL (25 °C)
Crystal structure orthorhombic (hexagonal above 413 °C)
heat capacity
142.1 J/mol K
Std molar
174.5 J/mol K
Std enthalpy of
−1329 kJ/mol
Gibbs free energy ΔG -1232 kJ/mol
EU Index 024-018-00-3
EU classification Carc. Cat. 2
Muta. Cat. 2
Repr. Cat. 2
Very toxic (T+)
Harmful (Xn)
Corrosive (C)
Dangerous for the environment (N)
R-phrases R45, R46, R60, R61, R21, R25, R26, R34, R42/43, R48/23, R50/53
S-phrases S53, S45, S60, S61
NFPA 704
Flammability code 0: Will not burn. E.g., water Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity (yellow): no hazard code Special hazard OX: Oxidizer. E.g., potassium perchlorateNFPA 704 four-colored diamond
Flash point Non-flammable
Related compounds
Other anions Sodium dichromate
Sodium molybdate
Sodium tungstate
Other cations Potassium chromate
Calcium chromate
Barium chromate
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Sodium chromate (Na2CrO4) is a yellow solid chemical compound used as a corrosion inhibitor in the petroleum industry,[1] a dyeing auxiliary in the textile industry,[1] as a wood preservative,[2] and as a diagnostic pharmaceutical in determining red blood cell volume.[3]

It is obtained from the reaction of sodium dichromate with sodium hydroxide. It is hygroscopic and can form tetra-, hexa-, and decahydrates. Sodium chromate, like other hexavalent chromium compounds, is toxic and carcinogenic.[1]

The substance is a strong oxidant. It is soluble in water,[4] producing a weakly basic solution.[5]

See also[edit]


  1. ^ a b c Gerd Anger, Jost Halstenberg, Klaus Hochgeschwender, Christoph Scherhag, Ulrich Korallus, Herbert Knopf, Peter Schmidt, Manfred Ohlinger (2005), "Chromium Compounds", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a07_067 
  2. ^ "Sodium chromate - Pesticide use statistics for 2005". PAN Pesticides Database. Retrieved 2008-06-20. 
  3. ^ Bracco Diagnostics Inc. "chromitope sodium (Sodium Chromate, Cr 51) injection, solution". DailyMed. Retrieved 2008-06-20. 
  4. ^ "Sodium chromate". inchem. Retrieved 2008-06-20. 
  5. ^ Record of Sodium chromate in the GESTIS Substance Database from the IFA