Bismuth trioxide

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Bismuth trioxide
IUPAC names
Bismuth(III) oxide
Bismuth trioxide
Other names
Bismuth sesquioxide
Bismuth trioxide
Bismuth Yellow
Dibismuth trioxide
Molar mass 465.96 g/mol
Appearance Yellow solid
Odor Odorless
Density 8.90 g/cm3
Melting point 817 °C (1,503 °F; 1,090 K)
Boiling point 1,890 °C (3,430 °F; 2,160 K)
Solubility Dissolves in acids
Vapor pressure ~0 mmHg
-271.6 J·mol-1·K-1
-578 kJ/mol
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Related compounds
Related compounds
Antimony(III) oxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Bismuth trioxide or bismuth(III) oxide. is a dense yellow solid that is used as a non-toxic alternative to lead oxides in pyrotechnic mixes. It has the chemical formula Bi2O3.



Like other oxides, on addition to an acid the bismuth salt and water are formed. It is therefore a useful stating point in creating bismuth compounds such as bismuth nitrate.

A bismuthate ion exists and it is a very powerful oxidizer, able to oxidize chromates and manganates. It can be produced from bismuth trioxide by heating with a molten alkali hydroxide.

Its reaction with magnesium and aluminium powders is exceptionally violent for a thermite, and will explode due to the density of the oxide and the low reactivity of bismuth, reaction similar to copper(II) oxide. Therefore this is not a viable way of producing the metal from the oxide as any metal produced is vaporized.

Pyrotechnic mixes of magnesium and bismuth trioxide are labelled "Dragon's Eggs", where pellets are designed to explode after a short period of burning.

Molten bismuth oxide is an extremely powerful oxidizer that can dissolve platinum.


A yellow solid that can appear with a slight green tinge in impure samples, Bi2O3 is remarkably dense.


Pyrotechnic supplies will most likely sell Bi2O3. It has no shipping restrictions, so pyrotechnic grade oxide can be found online reasonably priced, and it's often relative pure.


Burning bismuth metal by a blow torch is an uncontrolled way to make Bi2O3, and much of it escapes if there is not a good method of catching it as it is created.


  • Dragon's eggs
  • Explosive thermite



Bismuth trioxide, like most compounds, is comparatively a lot less toxic than lead compounds, but it is still inadvisable to breathe in metal vapors or large amounts of metal oxides.


In closed clean bottles, made of plastic or glass.


Can be dumped in trash or recycled.


Relevant Sciencemadness threads