The Case of the Disappearing Aluminum

Introduction:
Welcome to the case of the disappearing aluminum. We are going to determine the number of grams of copper that will be produced from an oxidation reduction reaction when you know the mass of Aluminum that reacted with a known amount of Copper (II) Sulfate pentahydrate and to compare this to the actual yield of copper. We will find the theoretical yield and then actual yield, thus giving us the percent yield. We will then conclude the lab.

Materials

• Aluminum Powder
• Copper (II) Sulfate
• Water
• Filter paper
• Scale
• Bunsen Burner
• Beaker

Safety: Aprons, goggles, forceps

Procedure:

1. Obtained a beaker
2. Added 90 mL of water to the beaker
3. Measured out 9.17 g of Copper (II) Sulfate to the water and began heating it on the bunson burner
4. Measured out .989 g of Aluminum powder
5. Stirred the Copper (II) Sulfate until dissolved, then added the aluminum powder
6. Continued heating until all was dissolved.
7. Filtered out the residue in a funnel
8. Cleaned equipment and put residue out to dry
9. Weighed residue
10. Found limiting reactant, theoretical yield, then compare to actual yield and that to find the percent yield.
11. Cleaned up and completed lab

Data Table

Item	Mass
Aluminum Powder	.989 g
Copper Sulfate	9.17 g
Coffee Filter	.89 g
Product + Filter Paper	3.4 g
Product (Copper)	2.51 g

Results:

Balanced Equation: 3Cu(II)SO₄ + 2Al --- 3Cu + Al₂(SO₄)₃

Limiting Reactant: Al

Actual Yield: 2.51 g of Cu

Theoretical Yield: 3.48 g of Cu

Percent Yield: 72%

Discussion: This was a lab that was meant to find the percent yield of the product. There were many steps in determining this. First by weighing the product we found the actual yield (2.51 g of Copper), then we found the limiting reactant which was aluminum and that led us to the theoretical yield of 3.48 g of Copper. We divided the actual by the theoretical and got 72%, which is not too bad meaning we did not waste the much in the reaction process. This was a single displacement reaction, because aluminum replaced copper in the the copper sulfate to make aluminum sulfate and copper was left as a precipitate. The formation of the precipitate and color change into red meant that it was indeed a chemical reaction.

Conclusion:
This lab created copper which we used to calculate several things. It helped us understand the percent yield, and it showed us how much is wasted because the actual yield is always less then the theoretical yield. We explored a way to calculate this by creating copper from copper sulfate and aluminum powder mixed together in water. It was a unique experience that helped put percent yield and chemical reactions on a visual scale. We got 72% of the theoretical yield in the actual, so we were pretty close, but there are some reasons that we did not get near the full amount. Perhaps the actual measurement was not as exact as it could of been, not all the copper precipitate might of been filtered out, perhaps there was some left in the copper aluminum solution, and a variety of other possible explanations. In short, our lab was a very informative lab, and helped us learn a lot about percent yield, theoretical yield, actual yield, and how they all relate to each other. The End.