Sodium bismuthate

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Sodium bismuthate
Kristallstruktur Perovskit.png
__ Na+ __ O2− __ Bi5+
Identifiers
CAS number 12232-99-4 N=
EC number 235-455-6
Jmol-3D images 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)
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 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[edit]

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[edit]

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:

2 NaBiO3 + H2O → 2 NaOH + Bi2O3 + 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[edit]

  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. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0080379419.