"Battle of metals" experiment
Aluminum foil Vs. Copper(II) sulfate
In chemistry, just like in life, there is constant competition. Some metals force others out of their bonds. In this colorful experiment, we show you the main rule of displacement of metals based on the example of the “battle” between aluminum and copper.
Reagents and equipment:
- aluminum foil;
- copper(II) sulfate;
- sodium chloride;
- distilled water;
First make a small cup out of aluminum foil and place in on the beaker. Then pour a blue solution of copper(II) sulfate and a transparent solution of sodium chloride into this cup. The solution turns green. After a few seconds, a violent reaction will start to take place, with the release of gas and a red-brown sediment on the surface of the aluminum foil. Gradually, the layer of aluminum foil disintegrates, and the remaining solution drips through the hole that appears.
Aluminum does not react with the solution of copper sulfate, as its surface is protected with a durable oxide film. When the solutions of copper(II) sulfate and sodium chloride are mixed, the complex salt of copper(II) chloride forms, which turns the solution green.
CuSO₄ + 4NaCl ⇆ Na₂[CuCl₄] + Na₂SO₄
Chloride ions can destroy the oxide film, as a result of which the aluminum starts to interact simultaneously with copper cations and water molecules:
2Al + 6H₂O → 2Al(OH)₃ + 3H₂
3Cu²⁺ + 2Al → 3Cu + 2Al³⁺
Aluminum forces the copper out of the bond, as aluminum is a more active metal than copper in the electrochemical series of metals. Thus, red metallic copper and gaseous hydrogen are released. This reaction takes place very intensively, and with the release of heat.
Before conducting the experiment, put on rubber gloves and protective glasses.
Warning! Substances of this experiment are toxic and highly dangerous for your health. Do not try this at home. Only under professional supervision.