Barium oxide

Barium oxide, BaO, is a white hygroscopic compound formed by the burning of barium in oxygen, although it is often formed through the decomposition of other barium salts.


 * 2Ba + O2 → 2BaO
 * BaCO3 → BaO + CO2

It transforms into barium hydroxide on contact with water.


 * BaO + H2O → Ba(OH)2

Uses
Barium oxide is used as a coating for hot cathodes, and in cathode ray tubes. It is used in the production of certain kinds of glass such as optical crown glass. It replaced lead oxide. Lead oxide was used to raise the refractive index, but it also raised the dispersive power. Barium oxide only raises the refractive index. Barium oxide also has use as an ethoxylation catalyst in the reaction of ethylene oxide and alcohols, which takes place 150 and 200°C.

Safety issues
Barium oxide is an irritant. If it contacts the skin or the eyes or is inhaled it causes pain and redness. However, it is more dangerous when ingested. It can cause nausea and diarrhea, muscle paralysis, cardiac arrhythmia, and can cause death. If ingested, medical attention should be sought immediately. Barium oxide also is dangerous to the environment. It is harmful especially to aquatic organisms