Calcium hydroxide
Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca(OH). It is a colorless crystal or white powder and is obtained when calcium oxide (called "lime" or "quicklime") is mixed, or slaked with water. It has many names including hydrated lime, caustic lime, builders' lime, slack lime, cal, or pickling lime. Calcium hydroxide is used in many applications, including food preparation, where it has been identified as E number E526. Limewater is the common name for a saturated solution of calcium hydroxide.
Hydroxide
"Ortho"-periodic acid can lose all its protons, eventually forming the periodate ion [IO]. It can also be protonated in strongly acidic conditions to give the octahedral ion [I(OH)], completing the isoelectronic series, [E(OH)], E = Sn, Sb, Te, I; "z" = −2, −1, 0, +1. Other acids of iodine(VII) that contain hydroxide groups are known, in particular in salts such as the "meso"periodate ion that occurs in K[IO(OH)]·8HO.