Barium Tetroxide, BaO₄

Schone suggested that the yellow compound, which is obtained from the monoperoxyhydrate without change of composition, probably represents a higher state of oxidation than the peroxide, i.e. Barium Tetroxide, BaO₄. Traube and Schulze regard it as a tetroxide, and, as in the case of the calcium tetroxide, suppose it to be comparable with the polysulphides, thus writing its formula as BaO₄.O₄. They never obtained samples containing more than 8 per cent, of tetroxide, but these were of a rather intense yellow, indicating that the pure substance would probably be very dark. A fairly high temperature is necessary to destroy the colour completely. As in the case of calcium tetroxide, no other means of oxidation than hydrogen peroxide can be used.