Copper(II) chlorate heated, giving off a yellow gas, which contains chlorine, oxygen and chlorine dioxide. A green solid is left that is a basic copper salt. Sulfur is highly reactive with copper chlorate, and it is important not to cross contaminate these chemicals, for example in pyrotechnic making. François-Marie Chertier used tetrammine copper chlorate to colour flames blue in 1843. This material was abbreviated TACC with formula Cu(NH)(ClO). TACC explodes on impact. The substance became known as Chertier'c copper for use in blue coloured pyrotechnics. However its deliquescence causes a problem. Mixtures with other metal salts can yield violet or lilac colours
Barium oxide at 1175K. The reaction was used as a large scale method to produce oxygen before the air separation became the dominant method in the beginning of the 20th century. The method was named after its inventors the Brin process. Barium oxide is made by heating barium carbonate. It may also be prepared by thermal decomposition of barium nitrate. Likewise, it is often formed through the decomposition of other barium salts. 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