Al + CuSO4 provides a fast and fascinating reaction to observe. In order to get the reaction going it is necessary to add some Cl- (chloride) ions to the mixture. These ions act as a sort of catalyst and were provided in the form of NaCl.
Note that the reaction is a bit more complicated than just a single displacement reaction where the Al displaces the Cu in CuSO4. Bubbles can be observed which cannot be explained by the equation (unbalanced):
Al(s) + CuSO4(aq) = Al2(SO4)3 + Cu(s)
The bubbles are actually hydrogen gas (H2) generated from the reaction of water with Aluminum. Therefore there are two reactions taking place at the same time. Lots going on here!
The CuSO4 was purchased online (one pound for about 9 USD delivered). The Al is aluminum foil as found in a supermarket. The NaCl was table salt.
