Chloric acid, barium salt
|3D model (Jmol)||Interactive image|
|Molar mass||304.23 g/mol|
|Density||3.18 g/cm3, solid|
|Melting point||413.9 °C (777.0 °F; 687.0 K) (decomposes)|
|27.5 g/100 ml (20 °C)|
|Safety data sheet||Barium Chlorate MSDS|
EU classification (DSD)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Barium chlorate, Ba(ClO3)2, is a white crystalline solid, the barium salt of chloric acid. It is an irritant and toxic, as are all soluble barium compounds. It is sometimes used in pyrotechnics to produce a green color. It also finds use in the production of chloric acid.
- BaCl2 + 2 NaClO3 → Ba(ClO3)2 + 2 NaCl
On concentrating and chilling the resulting mixture, barium chlorate precipitates. This is perhaps the most common preparation, exploiting the lower solubility of barium chlorate compared to sodium chlorate.
The above method does result in some sodium contamination, which is undesirable for pyrotechnic purposes, where the strong yellow of sodium can easily overpower the green of barium. Sodium-free barium chlorate can be produced directly through electrolysis:
- BaCl2 + 6 H2O → Ba(ClO3)2 + 6 H2
- 2 NH4ClO3 + BaCO3 + Q → Ba(ClO3)2 + 2 NH3 + H2O + CO2
The reaction initially produces barium chlorate and ammonium carbonate; boiling the solution decomposes the ammonium carbonate and drives off the resulting ammonia and carbon dioxide, leaving only barium chlorate in solution.
- Ba(ClO3)2 → BaCl2 + 3O2
Barium chlorate is used to produce chloric acid, the formal precursor to all chlorate salts, through its reaction with dilute sulfuric acid, which results in a solution of chloric acid and insoluble barium sulfate precipitate:
- Ba(ClO3)2 + H2SO4 → 2HClO3 + BaSO4
Both the chlorate and the acid should be prepared as dilute solutions before mixing, such that the chloric acid produced is dilute, as concentrated solutions of chloric acid (above 30%) are unstable and prone to decompose, sometimes explosively.
Barium chlorate, when burned with a fuel, produces a vibrant green light. Because it is an oxidizer, a chlorine donor, and contains a metal, this compound produces a green color that is unparalleled. However, due to the instability of all chlorates to sulfur, acids, and ammonium ions, chlorates have been banned from use in class C fireworks in the United States. Therefore, more and more firework producers have begun to use more stable compound such as barium nitrate and barium carbonate.
Barium chlorate is toxic to humans and can also harm the environment. It is very harmful to aquatic organisms if it is leached into bodies of water. Chemical spills of this compound, although not common, can harm entire ecosystems and should be prevented. It is necessary to dispose of this compound as hazardous waste. The Environmental Protection Agency (EPA) lists barium chlorate as hazardous.
- Perigrin, Tom. "Barium Chlorate". GeoCities. Archived from the original on 2007-10-30. Retrieved 2007-02-22.
- Wilson, Elizabeth. "C&EN: SCIENCE & TECHNOLOGY - WHAT'S THAT STUFF? FIREWORKS." WHAT'S THAT STUFF? FIREWORKS. Chemical and Engineering News, 2 July 2001. Web. 28 Jan. 2013.