“Green lantern” experiment
How to make Green lantern from aluminum foil and copper(II) chloride
Do you dream of becoming a superhero? We know the easiest way to do so! In this experiment you’ll see that you can get the Green Lantern without leaving the laboratory.
Wear protective gloves, a mask and glasses, and work in a well-ventilated room.
Reagents and equipment:
- saturated solution of copper(II) chloride;
- aluminum foil;
- conic flask;
Pour the solution of copper(II) chloride into the flask, then add balls of aluminum foil. The foil begins to dissolve violently, with the release of gas and a dark red sediment. Light it. Watch a green flame appear.
Aluminum is a rather inert metal in ordinary conditions, as it is covered with a durable protective oxide film. But in a solution of copper(II) chloride it dissolves violently, with the release of metallic copper and colorless hydrogen gas. This happens because the solution contains chloride ions which easily destroy the oxide film. As a result, the aluminum reacts with water molecules:
2Al + 6H₂O → 2Al(OH)₃ + 3H₂
It also forces copper ions out of copper(II) chloride:
2Al + 3Cu²⁺ → 3Cu + 2Al³⁺
If we light the hydrogen released, it will burn with a green flame because of the presence of copper ions.