Sodium bismuthate

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Sodium bismuthate

__ Na+ __ O2− __ Bi5+
Identifiers
CAS number 12232-99-4 N=

EC number 235-455-6
Jmol-3D images {{#if:[O-][Bi](=O)=O.[Na+]|Image 1
Properties
Molecular formula NaBiO3
Molar mass 279.97 g/mol
Appearance Light brown powder
Density 6.50 g/cm3
Solubility in water insoluble in cold, decomp. in hot water
Hazards
EU classification Harmful (Xn)
R-phrases R22, R36/37/38
S-phrases S26, S36
LD50 420 mg/kg (rat)
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Sodium bismuthate is the inorganic compound with the formula NaBiO3. It is a yellowish solid that is a strong oxidiser.[1] It is not soluble in cold water. It is one of the few sodium salts that is insoluble in water. It is commercially available however commercial samples may be a mixture of bismuth(V) oxide, sodium carbonate and sodium peroxide.[2]

Structure

Sodium bismuthate adopts a perovskite structure, consisting of octahedral Bi5+ centers with the Na+ centers occupying the cubic sites. The average Bi-O distance is 2.116 Å.[3]

Synthesis and reactions

Bismuth oxidizes to Bi(V) only with difficulty in the absence of alkali. For example, the simple oxide Bi2O5 remains poorly characterized. The preparation of this salt involves oxidizing a mixture of Bi2O3 and Na2O with air (source of O2):[4]

Na2O + O2 + Bi2O3 → 2 NaBiO3

The procedure is analogous to the preparation oxidation of manganese dioxide in alkali to give sodium manganate.

It oxidizes water, decomposing into bismuth(III) oxide and sodium hydroxide:

4 NaBiO3 + 2 H2O → 4 NaOH + 2 Bi2O3 + 3 O2

It is decomposed more rapidly by acids.

As a strong oxidizer, sodium bismuthate converts virtually any manganese compound to permanganate, which is easily assayed spectrophotometrically.[4] It is also used for lab-scale separation of plutonium.

Vial of NaBiO3.

References

  1. "Sodium bismuthate". Mallinckrodt Baker. 06/19/07. 
  2. Suzuki, Hitomi (2001). Organobismuth Chemistry. Elsevier. pp. 1–20. ISBN 978-0-444-20528-5. 
  3. N. Kumada, N. Kinomura, A.W. Sleight "Neutron powder diffraction refinement of ilmenite-type bismuth oxides: ABiO3 (A = Na, Ag)" Materials Research Bulletin 2000, volume 35, pp. 2397–2402. doi:10.1016/S0025-5408(00)00453-0
  4. 4.0 4.1 Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419. 
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