Microscale chemistry with a coin and a can
Mahmoud K. El-Marsafy, Peter Schwarz

2. Direct electron transfer from aluminium to copper ions (microscope)

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Photo 2.1 - 2.3
1 x 2 mm of the can closure (Al) in a drop of copper salt solution of experiment  1

A drop of the copper nitrate / table salt solution obtained from the Pfennig coin is placed on a  microscopic slide. A tiny piece of aluminium - cut from the closure of a Cola can-  is pushed into that drop.
It can be observed that small trees in the colour of copper are branching out.

                Reduction:            3 Cu2+(aq) +  6e- --> 3 Cu(s)
                 Oxidation:                             2 Al(s) --> 2 Al3+(aq) + 6e-
       Redox reaction:        3 Cu2+(aq)+ 2 Al(s) -->  3 Cu(s) +  2 Al3+(aq)

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