Barium ferrate hydrochloric acid, releasing chlorine. The irreversible reaction of digesting barium chromate with a solution of sodium ferrate forms barium ferrate, and the color of the solution is changed from red to yellow due to the sodium chromate that is also formed. Alkaline sulfates decompose barium ferrate that has not been dried, forming barium sulfate, ferric hydroxide and oxygen gas. Barium ferrate, therefore, appears to be one of the most insoluble salts known. Barium ferrate Barium ferrate is the chemical compound of formula BaFeO. This is a rare compound containing iron in the +6 oxidation state. The ferrate(VI) ion has two
Chemical element plants, the calcium in mollusc shells, or the iron in the hemoglobin in vertebrate animals' red blood cells. The concept of an "element" as an undivisible substance has developed through three major historical phases: Classical definitions (such as those of the ancient Greeks), chemical definitions, and atomic definitions. Ancient philosophy posited a set of classical elements to explain observed patterns in nature. These "elements" originally referred to "earth", "water", "air" and "fire" rather than the chemical elements of modern science. The term 'elements' ("stoicheia") was first used by the Greek philosopher Plato in about 360 BCE in his dialogue Timaeus,