| Reactions of Silicon |
 Reactions with water |
| A surface layer of oxide makes silicon unreactive to water and steam. |
| Reactions with air |
| Due to a thin layer of oxide on a sample of silicon it will not react with oxygen below temperatures of 900°C, above this the reaction with oxygen gives silicon dioxide.
|
Si(s) + O2(g) SiO2(s) |
| At temperatures above 1400°C the silicon will react with nitrogen to give silicon nitrides.
|
| 2Si(s) + N2(g)2SiN(s) |
| 3Si(s) + 2N2(g)Si3N4(s) |
| Reactions with halogens |
| Silicon reacts vigorously with all the halogens to form tetrahalides, the reaction with fluorine takes place at room temperature, the others require heating over 300°C.
|
| Si(s) + 2F2(g)SiF4(g) |
| Si(s) + 2Cl2(g)SiCl4(g) |
| Si(s) + 2Br2(l)SiBr4(l) |
| Si(s) + 2I2(l)SiI4(s) |
| Reactions with acids |
| Under normal conditions silicon does not react with most acids, but is dissolved by hydrofluoric acid. |
| Si(s) + 6HF(aq)[SiF6]2-(aq) + 2H+(aq) + 2H2(g) |
| Reactions with bases |
| Silicon is attacked by bases such as aqueous sodium hydroxide to give silicates. |
| Si(s) + 4NaOH(aq)[SiO4]4-(aq) + 4Na+(aq) + 2H2(g) |
Si(s) + 2H2O