In chemistry, plumbite is the PbO2−
2 oxyanion or hydrated forms, or any salt containing this anion. In these salts, lead is in the oxidation state +2. It is the traditional term for the IUPAC name plumbate(II).
For example, lead(II) oxide (PbO) dissolves in alkali to form salts containing the HPbO−
Lead(II) hydroxide also dissolves in excess alkali to form the Pb(OH)4−
The plumbite ion is a weak reducing agent. When it functions as one, it is oxidized to the plumbate ion.