| Reactions of Cobalt |
 Reactions with water |
| Water has little or no effect on cobalt. However, the reaction of red-hot cobalt and steam produces cobalt(II) oxide. |
2Co(s) + O2(g) 2CoO(s) |
| Reactions with air |
| Cobalt is not very reactive with air. Cobalt will not react directly with nitrogen. Heating will produce cobalt oxide.
|
| 3Co(s) + 4O2(g)2Co3O4(s) |
| Heating above 900°C will result in cobalt(II) oxide being formed. |
| 2Co(s) + O2(g)2CoO(s) |
| Reactions with halogens |
| Cobalt reacts with chlorine, bromine and iodine to form cobalt dihalides.
|
| Co(s) + Cl2(g)CoCl2(s) |
| Co(s) + Br2(l)CoBr2(s) |
| Co(s) + I2(s)CoI2(s) |
| Reactions with acids |
| Cobalt metal dissolves in dilute sulphuric acid to form solutions containing the Co(II) ion and hydrogen gas.
|
| Co(s) + H2SO4(aq)Co2+(aq) + SO42-(aq) + H2(g) |
Co2+