| Reactions of Nickel |
 Reactions with water |
| Nickel does not react with water under normal conditions. |
| Reactions with air |
| Nickel 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) |
| Reactions with halogens |
| Nickel does react with fluorine gas but only slowly which makes nickel an important metal for containers of fluorine.
|
| Nickel reacts with chlorine, bromine and iodine to form nickel(II) dihalides.
|
| Ni(s) + Cl2(g)NiCl2(s) |
| Ni(s) + Br2(g)NiBr2(s) |
| Ni(s) + I2(g)NiI2(s) |
| Reactions with acids |
| Nickel metal dissolves slowly in dilute sulphuric acid to form solutions containing the aquated Ni(II) ion together with hydrogen gas.
|
| Ni(s) + H2SO4(aq)Ni2+(aq) + SO42-(aq) + H2(g) |
| Reactions with bases |
| Nickel does not react with aquaous sodium hydroxide. |
| Reduction Potentials |
| Balanced half-reaction |
E0 / V
|
Ni2+ + 2e- Ni(s) |
-0.250 |
| NiO2(s) + 4H+ + 2e-Ni2+ + 2H2O
|
+1.593 |
| NiO2(s) + 2H2O + 2e-Ni(OH)2(s) + 2OH-
|
+0.49 |
| Ni2O3(s) + 6H+ + 2e-2Ni2+ + 3H2O
|
+1.753 |
| Ni3O4(s) + 2H2O + 2e-3HNiO2- + H+ |
-0.718 |
| Ni3O4(s) + 8H+ + 2e-3Ni2+ + 4H2O
|
+1.977 |
| HNiO2- + 3H+ + 2e-Ni(s) + 2H2O
|
+0.648 |
| Ni(CN)42- + e-Ni(CN)3- + CN- |
-0.4 |
| NiO42- + 8H+ + 4e-Ni2+ + 4H2O
|
+1.8 |
| Ni(NH3)62+ + 2e-Ni(s) + 6NH3 |
-0.49 |
| NiS(s) (alpha) + 2e-Ni(s) + S2- |
+0.76 |
| NiS(s) (gamma) + 2e-Ni(s) + S2- |
-0.99 |
