Selenium trioxide
Selenium trioxide, also known as selenium(VI) oxide and selenic oxide, is a chemical compound. Its chemical formula is SeO3. It contains selenium in its +6 oxidation state. It also contains oxide ions.
Properties[change | change source]
Selenium trioxide is a white solid. It evaporates easily. It dissolves easily in water. It is not stable and breaks down to make selenium dioxide and oxygen when it is heated. It is a powerful oxidizing agent like all selenates. It dissolves in water to make selenic acid.
Preparation[change | change source]
It can be made by reacting potassium selenate with sulfur dioxide. It can also be made by dehydrating (removing the water from) selenic acid with a strong dessicant, like phosphorus(V) oxide.