Zinc - 30Zn: reactions of elements
Reaction of zinc with air
Zinc metal tarnishes in moist air. Zinc metal burns in air to form the white zinc(II) oxide, a material that tirns yellow on prolonged heating.
2Zn(s) + O2(g) → 2ZnO(s) [white]
Reaction of zinc with water
Zinc does not react with water.
Reaction of zinc with the halogens
Zinc dibromide, zinc(II) dibromide, ZnBr2, and zinc diiodide, zinc(II) dibiodide, NiI2, are formed in the reactions of zinc metal and bromine, Br2, or iodine, I2.
Zn(s) + Br2(g) → ZnBr2(s) [white]
Zn(s) + I2(g) → ZnI2(s) [white]
Reaction of zinc with acids
Zinc metal dissolves slowly in dilute sulphuric acid to form solutions containing the aquated Zn(II) ion together with hydrogen gas, H2. In practice, the Zn(II) is present as the complex ion [Zn(OH2)6]2+.
Zn(s) + H2SO4(aq) → Zn2+(aq) + SO42-(aq) + H2(g)
The reacts of zinc with oxidizing acids such as nitric acid, HNO3, are complex and depend upon precise conditions.
Reaction of zinc with bases
Zinc metal dissolves in aqueous alkalis such as potassium hydroxide, KOH, to form zincates such as [Zn(OH)4]2-. The resulting solutions contain other species as well.