What is Cobalt(II,III) oxide?
[[File:Oxid kobaltnato-kobaltičitý.PNG|thumb|Cobalt(II,III) oxide]] '''Cobalt(II,III) oxide''' is a [[chemical compound]]. It contains some (1 atom) cobalt in the +2 [[oxidation state]] and some (2 atoms) in the +3 oxidation state. Its chemical formula is Co<sub>3</sub>O<sub>4</sub>. It contains [[cobalt]] and [[oxide]] [[ion]]s. ==Properties== It is a black solid. It reacts with [[hydrochloric acid]] to make [[chlorine]] and [[cobalt(II) chloride]]. ==Preparation== It is made when [[cobalt(II) oxide]] is heated to {{convert|600|C|F}}. When it is heated to {{convert|900|C|F}}, it turns back into cobalt(II) oxide. ==Uses== It has been used in research for making [[hydrogen]]. ==Safety== It is irritating to the skin. It can cause harm if swallowed. It dissolves in the stomach acid. ==Related pages== *[[Iron(II,III) oxide]] *[[Cobalt(III) oxide]] [[Category:Cobalt compounds]] [[Category:Oxides]]