Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: A polyatomic ion is an ion consisting of a molecule with covalently bonded atoms or of a metal complex that can be considered as acting as a single unit in the context of acid/base chemistry or in the formation of salts. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...

OH⁻

It has a charge of −1. Hydroxide is one of the simplest of the polyatomic ions.

A group of bases containing hydroxide are called hydroxide bases. Hydroxide bases will dissociate into a cation and one or more hydroxide ions in water, making the solution basic. This makes hydroxides alkalis, which may undergo neutralisation reactions with acids. In general acid-alkali reactions can be simplified to The common (Arrhenius) definition of a base is a chemical compound that absorbs hydronium ions when dissolved in water (a proton acceptor). ... For the battery, see alkaline battery The word alkali can mean:- In chemistry, an alkali is a specific type of base, formed as a carbonate, hydroxide or other ionic salt of an alkali metal or alkali earth metal element. ... Neutralization is a chemical reaction, also called a water forming reaction, in which an acid and a base or alkali (soluble base) react and produce a salt and water. ... For alternative meanings see acid (disambiguation). ... An Acid-Alkali Reaction is a special case of an acid-base reaction, where the base used is also an Alkali. ...

OH⁻(aq) + H⁺(aq) → H₂O

by omitting spectator ions. In chemistry, hydronium is the common name for the cation H3O+. // Nomenclature According to IUPAC ion nomenclature, it should be referred to as oxonium. ... Water has the chemical formula H2O, meaning that one molecule of water is composed of two hydrogen atoms and one oxygen atom. ... A spectator ion is a ion in a chemical reaction that remains unchanged after the reaction has occured compared to beforehand. ...

Hydroxides and hydroxide ions are relatively common. Many useful chemicals and chemical processes involve hydroxides or hydroxide ions, such as sodium hydroxide (lye) is used in industry as a strong base, potassium hydroxide is used in agriculture. Iron hydroxide minerals such as goethite and limonite have been used as low grade brown iron ore The aluminium ore rock, bauxite, is composed largely of aluminium hydroxides. Flash point non flammable Supplementary data page Structure and properties n, εr, etc. ... The common (Arrhenius) definition of a base is a chemical compound that absorbs hydronium ions when dissolved in water (a proton acceptor). ... The chemical compound potassium hydroxide, (KOH) sometimes known as caustic potash, potassa, potash lye, and potassium hydrate, is a metallic base. ... Iron oxide pigment There are a number of iron oxides: Iron oxides Iron(II) oxide or ferrous oxide (FeO) The black-coloured powder in particular can cause explosions as it readily ignites. ... Goethite is a hydrated iron oxide, HFeO2 or Fe3+O(OH) (known as lepidocrocite). ... Limonite Limonite Limonite is a ferric hydrate of varying composition, the generic formula is frequently written as FeO(OH)·nH2O, although this is not entirely accurate as Limonite often contains a varying amount of oxide compared to hydroxide. ... Iron ore (Banded iron formation) Manganese ore Lead ore Gold ore An ore is a mineral deposit containing a metal or other valuable resource in economically viable concentrations. ... General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ... Bauxite with penny Bauxite (pebbly) Bauxite is a naturally occurring, heterogeneous material composed primarily of one or more aluminium hydroxide minerals, plus various mixtures of silica, iron oxide, titania, aluminium silicates, and other impurities in minor or trace amounts. ...

See also

• Hydronium
• Oxide