H₂(g) + I₂(g) ⇌ 2HI(g)
Explanation:
* H₂(g): Hydrogen gas, a colorless and odorless gas.
* I₂(g): Iodine vapor, a purple gas.
* HI(g): Hydrogen iodide, a colorless gas with a pungent odor.
* ⇌: This symbol indicates a reversible reaction, meaning the reaction can proceed in both directions.
Conditions:
This reaction is usually carried out at elevated temperatures (around 400°C) and in the presence of a catalyst (like platinum).
Key points about the reaction:
* Endothermic: The forward reaction (formation of HI) is endothermic, meaning it absorbs heat.
* Equilibrium: The reaction reaches a state of equilibrium where the rates of the forward and reverse reactions are equal.
* Le Chatelier's Principle: The equilibrium can be shifted by changing factors like temperature, pressure, or concentration of reactants or products.
