Oxide copper, so it displaces copper (II) oxide to form zinc oxide: Apart from metals, hydrogen can also displace metal oxides to form hydrogen oxide, also known as water: Since metals that are reactive form oxides that are stable, some metal oxides must be electrolyzed to be reduced. This includes sodium oxide, potassium oxide, calcium oxide, magnesium oxide, and aluminium oxide. The oxides must be molten before immersing graphite electrodes in them: Oxides typically react with acids or bases, sometimes both. Those reacting only with acids are labeled basic oxides. Those reacting only by bases are called "acidic oxides". Oxides that
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