Reaction:
* CuCl₂ (aq) + 2Al (s) → 2AlCl₃ (aq) + 3Cu (s)
Explanation:
* Aluminum (Al) is more reactive than copper (Cu). This means aluminum has a stronger tendency to lose electrons and form positive ions.
* In the reaction, aluminum atoms displace copper ions from the copper chloride solution.
* Aluminum atoms lose electrons and form aluminum ions (Al³⁺), which then combine with chloride ions (Cl⁻) to form aluminum chloride (AlCl₃).
* The copper ions (Cu²⁺) gain electrons and become copper atoms (Cu), which precipitate out of the solution as a reddish-brown solid.
Observations:
* You'll observe a color change in the solution, as the blue copper chloride solution turns clear or slightly yellowish.
* You'll also see a reddish-brown coating forming on the aluminum foil, which is the deposited copper metal.
* The reaction is exothermic, meaning it releases heat and the solution may feel warm.
Scientific Conclusion:
* This reaction demonstrates the relative reactivity of metals. Aluminum, being more reactive, displaces copper from its compound.
* The single displacement reaction produces a new compound (aluminum chloride) and a new element (copper).
* The reaction is a clear example of a redox reaction (oxidation-reduction reaction), where electrons are transferred from aluminum to copper.
Additional Notes:
* The reaction is often used in introductory chemistry labs to demonstrate single displacement reactions and the concept of reactivity series.
* The amount of copper deposited depends on the amount of copper chloride used and the surface area of the aluminum foil.
* The reaction can be quite vigorous, so it's important to perform it in a safe environment, with appropriate safety precautions.
