Bismuth(III) Oxide

Chemical properties

Heavy, Yellow Powder

Chemical properties

Bismuth(III) oxide is the compound produced by heating the metal, or its carbonate, in air. It is definitely a basic oxide, dissolving readily in acid solutions, and unlike the arsenic or antimony compounds, not amphiprotic in solution, although it forms stoichiometric addition compounds on heating with oxides of a number of other metals. It exists in three modifications, white rhombohedral, yellow rhombohedral, and gray-black cubical. Bismuth(II) oxide, BiO, has been produced by heating the basic oxalate.

Physical properties

Yellow monoclinic crystal or powder; density 8.90 g/cm³; melts at 817°C; vaporizes at 1,890°C; insoluble in water; soluble in acids.

Occurrence

Bismuth trioxide occurs in nature as mineral bismite. The oxide is used in fireproofing of papers and polymers; in enameling cast iron ceramic; and in disinfectants.

The Uses of Bismuth(III) Oxide

Bismuth(III) oxide is used in the preparation of BiFeO3perovskite nanoparticles. It finds use in disinfectants, magnets, glass, rubber, vulcanization, fireproofing papers and polymers and catalysts. Bismuth trioxide brings about the "dragon's eggs" effect in fireworks, as a replacement of red lead. Bismuth(III) compounds are attractive reagents and catalysts in organic synthesis because of their low cost and ease of handling. Bismuth trioxide nanoparticles also play an important role in high energy gas generators. The alpha crystalline form of bismuth(III) oxide has p-type electronic conductivity.

The Uses of Bismuth(III) Oxide

In disinfectants, magnets, glass, rubber vulcanization; in fireproofing of papers and polymers; in catalysts.

Preparation

Bismuth trioxide is commercially made from bismuth subnitrate. The latter is produced by dissolving bismuth in hot nitric acid. Addition of excess sodium hydroxide followed by continuous heating of the mixture precipitates bismuth trioxide as a heavy yellow powder. Also, the trioxide can be prepared by ignition of bismuth hydroxide.

General Description

Bismuth (III) oxide is a yellow, monoclinic crystalline powder. It is insoluble in water and hydroxide solutions but dissolves in acids to form bismuth (III) salts. It can be prepared by heating bismuth in air or by heating hydroxides, carbonates or nitrates of bismuth.