Chemical reactions of the elements
Reaction of nickel with air
Nickel metal does not react with air under ambient conditions. Finely divided nickel metal reacts readily with air and in this form may be pyrophoric.
At higher temperatures, the reaction between nickel metal and oxygen appears not to proceed to completion but gives some nickel(II) oxide.
2Ni(s) + O2(g) → 2NiO(s)
Reaction of nickel with water
Nickel metal does not react with water under normal conditions.
Reaction of nickel with the halogens
Nickel metal does react with fluorine gas, F2, but only slowly. This makes nickel an important metal for containers of fluorine.
The dichloride, NiCl2, dibromide, NiBr2, and diiodide, NiI2, are formed in the reactions of nickel metal and chlorine, Cl2, bromine, Br2, or iodine, I2.
Ni(s) + Cl2(g) → NiCl2(s) [yellow]
Ni(s) + Br2(g) → NiBr2(s) [yellow]
Ni(s) + I2(g) → NiI2(s) [black]
Reaction of nickel with acids
Nickel metal dissolves slowly in dilute sulphuric acid to form solutions containing the aquated Ni(II) ion together with hydrogen gas, H2. In practice, the Ni(II) is present as the complex ion [Ni(OH2)6]2+.
Ni(s) + H2SO4(aq) → Ni2+(aq) + SO42-(aq) + H2(g)
The strongly oxidizing concentrated nitric acid, HNO3, reacts on th surface of iron and passivates the surface.
Reaction of nickel with bases
Nickel does not react with aquaous sodium hydroxide.