Reactions between iron and oxygen
Iron can form many different oxides. When iron is burnt and reacts with oxygen, it forms either iron (III) oxide, more commonly known as rust, or tri-iron tetroxide.
| Iron | + | Oxygen | → | Iron (III) oxide |
| 4Fe | + | 3O2 | → | 2Fe2O3 |
| Iron | + | Oxygen | → | Tri-iron tetroxide |
| 3Fe | + | 2O2 | → | Fe3O4 |
When iron burns it produces a bright orange flame. The iron (III) oxide produced has an orangey brown colour, while tri-iron tetroxide is dark grey or black. Iron oxide is insoluble in water.
