| Barium Percarbonate, BaCO4.aq., is obtained as a light yellow compound by cooling a suspension or solution of barium peroxide to 0° C. and treating with carbon dioxide, the peroxide being always in excess. It is hydrated, and is not to be regarded as BaCO3.H2O2, because neither alcohol nor ether extracts hydrogen peroxide from it, and it only gives up hydrogen peroxide slowly on treatment with water. It is a convenient reagent for the preparation of neutral hydrogen peroxide by treatment either with water or with an acid producing an insoluble barium salt. |