Tin(II) oxide

Tin(II) oxide, also known as stannous oxide or tin monoxide is a chemical compound with the formula SnO. Its molar mass is 134.71 g/mol. It comes in two forms, a pale white hydrated form and a blue-black anhydrous form. The hydrated form can be dehydrated by heating it gently. There is also an unstable red form. Tin(II) oxide is made by reacting an alkali with tin(II) chloride. This makes the hydrate. Tin(II) oxide burns in air when strongly heated, making a green flame and tin dioxide fumes. It is a reducing agent. It is used to make ruby glass, touchscreens, catalysts for esterification, and other tin compounds. When heated in a vacuum or an inert atmosphere tin(II) oxide (oxidation state of 2) disproportionates into tin metal (oxidation state of 0) and tin dioxide (oxidation state of 4). The electronic band gap of tin(II) oxide is between 2.5eV and 3eV.