Chlorine Gas - How to Prepare Chlorine Gas

These are instructions for preparing chlorine gas (Cl₂) from potassium permanganate and concentrated hydrochloric acid.

Reactants

potassium permanganate
concentrated hydrochloric acid

Gas Preparation

Add concentrated hydrochloric acid dropwise onto a small quantity of potassium permanganate crystals (in a flask). Collect the chlorine gas by upward displacement of air in a hood. Use proper safety precautions. Concentrated hydrochloric acid is extremely caustic. Chlorine gas is toxic.

Reaction

6HCl + 2KMnO₄ + 2H⁺ --> 3Cl₂ + 2MnO₂ + 4H₂O + 2K⁺