Sodium bismuthate(V), 85%

Sodium bismuthate is the inorganic compound with the formula NaBiO3. It is a yellowish solid that is a strong oxidiser. It is not soluble in cold water, which is sometimes convenient since the reagent can be easily removed after the reaction. 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. A related compound with the approximate formula Na3BiO4 also exists.

Bismuth oxidizes to the +V oxidation state only with difficulty – the simple oxide Bi2O5 remains poorly characterized – and in the absence of alkali. The preparation of this salt involves oxidizing a mixture of Bi2O3 and Na2O with air (as the source of O2):

Na2O + O2 + Bi2O3 → 2 NaBiO3

The procedure is analogous to the preparation oxidation of manganese dioxide in alkali to give sodium manganate. Sodium bismuthate 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. It is also used for lab-scale separation of plutonium.