Cucl3 Synthesis Lab

Qualitative question: Was there any CuCl2 left? There was no CuCl2 left, so the reaction went to completion. When the NH4OH was added to the solution, it did not turn blue. When NH4OH is added to a solution with copper in it, the solution should turn a cobalt blue color. However, the solution created a gel that indicates that AlCl3 was in solution, and there was minimal color change (caused by the change in the way light passes through gel). Due to the absence of blue, it can reasonably be concluded that there was no copper left. In addition, when the solution was being dried, it became yellow and then formed yellow crystals. The concentrated solution was a yellow color, but CuCl2 is blue in solution. In addition, dried CuCl2 is blue, and there was no evidence of any blue crystals, or even green crystals. All of these factors prove that there was no CuCl2 left, therefore the reaction went to completion.

Our calculations said that 2.29 grams of AlCl3 were produced, however this was inaccurate. This lab uses aluminum foil, which is impure. These impurities(mainly iron) were also metals higher than copper on the activity series, so they also single displaced copper. The basis for this claim is that the dried AlCl3 was yellow. According to further study, when AlCl3 is yellow, it is contaminated with FeCl3. The majority of aluminum foil contains 0.5%-1.5% iron, so when the aluminum foil was put into the solution the iron formed FeCl3. Because the mass that was taken of both of these chemicals, the data was inaccurate. Due to these inaccuracies the data must be