Oxidation states of the metal in the minerals smithsonite and hemimorphite, respectively are:
II, IV in smithsonite and II in hemimorphite
II, IV in smithsonite and IV in hemimorphite
IV in smithsonite and II, IV in hemimorphite
II in smithsonite and II, IV in hemimorphite
Smithsonite is a mineral composed of zinc carbonate , while hemimorphite is a mineral composed of zinc silicate . In these minerals, the oxidation state of the metal zinc varies.
In smithsonite, the oxidation states of the zinc ions are primarily +II and +IV. The carbonate ion carries a -2 charge, so to balance the charges in the compound, zinc can have an oxidation state of +II. However, there is evidence of some zinc ions in smithsonite having an oxidation state of +IV. This is due to the presence of zinc vacancies (missing zinc ions) in the crystal structure, which can result in some zinc ions being oxidized to the +IV state.
In hemimorphite, the oxidation state of the zinc ions is primarily +II . The silicate ion and hydroxide ion in hemimorphite do not contribute to the oxidation state of the zinc. Therefore, the oxidation state of zinc in hemimorphite is solely +II.