| Reactions of Carbon |
 Reactions with water |
| Carbon, either as graphite or diamond does not react with water under normal conditions. Under more forceful conditions, the
reaction becomes important. In industry, water is blown through hot coke. The resulting gas is called water gas and is a mixture
of hydrogen (H2, 50%), carbon monoxide (CO, 40%), carbon dioxide (CO2, 5%), nitrogen and methane (N2 + CH4, 5%). It is an important feedstock gas for the chemical industry.
|
C + H2O CO + H2 |
| This reaction is endothermic which means that the coke cools down during the reaction. To counteract this, the steam flow is replaced by air to reheat
the coke allowing further reaction.
|
| Reactions with air |
| Carbon, as graphite, burns in oxygen to form gaseous carbon(IV) dioxide. Carbon, as diamond, also burns in air when heated to 600-800°C to also form carbon(IV)
oxide.
|
| C(s) + O2(g)CO2(g) |
| When the air or oxygen is restricted then incomplete combustion to carbon monoxide (CO) occurs.
|
| 2C(s) + O2(g)2CO(g) |
| Reactions with halogens |
| Graphite reacts with fluorine (but none of the other halogens) at high temperatures to make a mixture of carbon tetrafluoride, CF4, together with some C2F6 and C5F12.
|
| C(s) + excess F2(g)CF4(g) + C2F6 + C5F12 |
| Reactions with acids |
| Graphite reacts with hot concentrated nitric acid to form mellitic acid, C6(CO2H)6.
|
| |
CO(g) + H2O