Manganese(VII) oxide is a chemical compound represented by the molecular formula Mn2O7. It is also known as manganese heptoxide, manganic oxide and dimanganese heptoxide. At room temperature it appears as a dark red oil.
One molecule of manganese(VII) oxide contains two atoms of manganese and seven atoms of oxygen. It has molar mass of about 221.87 grams per mole and a density of 2.79 grams per cubic centimeter. It can be produced through a reaction of potassium permanganate and sulfuric acid. The compound is explosive when heated past 55 degrees Celsius. It has a melting point of 6 degrees Celsius. Manganese(VII) oxide ionizes when it reacts with sulfuric acid.