Magnesium oxide Magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of and consists of a lattice of Mg ions and O ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + HO → Mg(OH)), but it can be reversed by heating it to separate moisture. Magnesium oxide was historically known as magnesia alba (literally, the white mineral from magnesia – other sources give magnesia alba as MgCO), to differentiate it from "magnesia
Ethylene oxide oxide with compounds containing active methylene group leads to the formation of butyrolactones: Ethylene oxide enters into the Friedel–Crafts reaction with benzene to form phenethyl alcohol: Styrene can be obtained in one stage if this reaction is conducted at elevated temperatures () and pressures (), in presence of an aluminosilicate catalyst. A series of polynomial heterocyclic compounds, known as crown ethers, can be synthesized with ethylene oxide. One method is the cationic cyclopolymerization of ethylene oxide, limiting the size of the formed cycle: To suppress the formation of other linear polymers the reaction is carried out in a highly dilute