Aluminum & Copper(II) Sulfate Redox Lab

Introduction:
The purpose of this lab is 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 2 sulfate pentahydrate and to compare this to the actual yield of copper.

Materials and Setup:

• measured sample of aluminum foil
• measure amount of copper sulfate pentahydrate
• 80 ml beaker
• Bunsen burner
• Striker
  
• stirring rod
• flask
• funnel
• coffee filter
• water
• safety goggles
• safety apron
• Scale
  

1. react the the sample of aluminum foil and copper sulfate pentahydrate in an aqueous medium sized beaker; stirring frequently. filter, dry and weigh the resulting product.
   

Procedure:

1. obtain a medium sized ( 80 ml) beaker
2. add 80 ml of water to the beaker; set up apparatus to heat your mixture over a Bunsen burner to begin heating.
3. Measure out 10 g of Copper 2 Sulfate pentahydrate ( CuSO4. 5 H2O) and record the mass in the data table. Then slowly add the crystals to the heating water.
4. with a glass stirring rod, stir the solution until the copper 2 sulfate pentahydrate is dissolved.
5. While the copper Sulfate Crystals are dissolving one member of the group can go and get the Aluminum Powder. Carefully weigh out the powder to weight between 0.4-0.7 grams. Record the mass exactly into the data table (thousandths place).
6. Carefully add the powder to the hot solution with continuous stirring until it is all in the beaker.
7. Stirring frequently allow the reaction to occur until you can't see anymore aluminum. This will take 15 to 20 minutes so be patient. Once you can't see anymore Aluminum, heat an additional 3 to 4 minutes, then remove from the heat.
   
8. Write your names around the edge of a filter paper (so you can claim it later), weight and record the mass in the data table.
9. Use the filter paper and your funnel to filter the residue in the beaker, catching the filtrate into the Erlenmeyer flask provided.
10. Rinse out your beaker with a small (amount just covering the bottom of the beaker) of water to be sure you obtained all of the product/residue.
11. Remove the filter paper from the funnel and spread it out on a paper towel to dry overnight.
12. Clean and dry the glassware. Be sure the propane is turned of and Bunsen burner disconnected and put away. Straighten up your area.
13. Upon returning the next day, weigh the filter paper and dry residue and record the mass in the data table. Throw the filter paper and residue away.
14. Construct a Data Table with the following parts:
1. Mass of Copper(II) Sulfate Pentahydrate
2. Mass of Aluminum foil
3. Mass of Coffee Filter
4. Mass of dry residue/product + Filter Paper
   

Analysis:

Mass of Copper(II) Sulfate Pentahydrate	10.01g
Mass of Aluminum foil	0.68g
Mass of Coffee Filter	.90g
Mass of dry residue/product + Filter Paper	3.49g

1. Write the balanced reaction equation.
1. 3CuSO4 + 2Al --> 3Cu + Al2(SO4)3
2. Write the Net Ionic Equation.
1. 3CuSO4(s) + 2Al(s) --> 3Cu + Al2(SO4)3(s)
   
3. What is the reducing agent and what is the oxidizing agent?
1. Reducing: Aluminum; Oxidizing: Copper Sulfate Pentahydrate
   
4. Use the Mass of the Aluminum powder and calculate the mass of the copper you theoretically would form.
   
1. 22.1g Al X 1 mol Al/26.98g Al X 1 mol Cu/1 mol Al X 63.55g Cu/1 mol Cu = 78.1g Cu
   
5. Subtract the filter paper from the dry residue/product in the data table below. This is your actual yield of copper.
1. 3.49g
   
6. Calculate the percent yield of the experiment.
   
1. 78.1g Cu = (actual)/4.3 Al2(SO4)3 = 335.83
   
7. Give three reasons of why the amount of copper that should have formed and the amount of copper that actually formed might be different.
1. Different temperatures
2. Different measurements
3. Different materials
   

A Surprising Twist

• Our lab is a prime example of what NOT to do.
• We performed the lab according to everything we were supposed to do, but we missed one minor detail. Written on the board was the measurement of 0.4-0.7 grams of Aluminum, but we were mistaken for we did not see the decimal point.
• At first the lab seemed fine and everything was going according to what was said would be done. But then our solution bubbled to such an exceeding amount that it overflowed the beaker and spilled all along the counter-top.
• We have learned a valuable lesson from this mistake and we would advise that you learn from our mistake as well and not make it yourself. We have learned to properly read directions and properly weigh the material placed in the concoction.