When iron and chlorine are heated together, the compound formed is Iron(III) chloride.
Understanding the Reaction
The reaction between iron and chlorine is a direct combination reaction that occurs under specific conditions, primarily heating. Chlorine is a strong oxidizing agent, and when it reacts with iron, it oxidizes the iron to its +3 oxidation state, leading to the formation of Iron(III) chloride.
Key Reactants and Products
This chemical process involves elemental iron and gaseous chlorine combining to yield a new compound.
| Reactant | Chemical Formula | State (at reaction conditions) |
|---|---|---|
| Iron | Fe | Solid (s) |
| Chlorine | Cl₂ | Gas (g) |
| Product | Chemical Formula | State (at room temperature) |
|---|---|---|
| Iron(III) chloride | FeCl₃ | Solid (s) |
The Chemical Equation
The balanced chemical equation for the reaction between iron and chlorine when heated is:
2Fe(s) + 3Cl₂(g) → 2FeCl₃(s)
This equation indicates that two atoms of solid iron react with three molecules of gaseous chlorine to produce two molecules of solid Iron(III) chloride. The heating provides the activation energy necessary for this exothermic reaction to proceed efficiently.
Properties of Iron(III) Chloride
Iron(III) chloride, also known as ferric chloride, is an industrial chemical with several notable properties:
- Appearance: It typically appears as dark green crystals by reflected light, but purple-red by transmitted light. Anhydrous Iron(III) chloride is highly hygroscopic, readily absorbing moisture from the air to form hydrated forms.
- Solubility: It is highly soluble in water, forming a strong acidic solution due to hydrolysis. It is also soluble in various organic solvents like alcohol, acetone, and ether.
- Uses:
- Water treatment: Used as a flocculant in sewage treatment and drinking water production.
- Etching: Employed in the etching of copper for printed circuit boards (PCBs).
- Catalyst: Serves as a catalyst in certain organic reactions.
- Medical applications: Historically used as a coagulant in medicine for minor bleeding.
