Copper Chloride Experiment
By: Chase W. Connor G. and Carter B.
Objective
Determine the moles of copper and chlorine in our sample and establish the proper chemical formula.
Procedure
Step 1
Measure and record the mass of a crucible. Place 1 g of copper chloride hydrate in the crucible. Break any large pieces of the hydrate with a spatula. Record mass of the compound in the crucible.
Step 2
Set up a ring stand with a clay triangle on it. Place the crucible on the triangle and heat it slowly with a lab burner. Do not overheat. The color should change from blue-green to brown. Once it's brown, heat it for another 2 minutes. Remove and turn off the burner and allow the crucible to cool for 10 minutes.
Step 3
Reheat the sample IF you see any blue-green crystals. Record the mass of the cool crucible of your copper chloride sample.
Step 4
Transfer the solide to a 50 mL beaker. Rinse out the crucible with two 8 mL aliquots of water and pour them into the beaker. Swirl the beaker to dissolve the solid. Place a coiled aluminum wire that is about 20 cm long into the beaker. The reaction will take about 30 minutes to complete.
Step 5
Once the reaction is done, the solution should be colorless. Add 5 drops of 6 M HCl solution to dissolve any insoluble aluminum salts (handle with care, as it will cause painful burns if it comes into contact with skin). Use a glass stirring rod to scrap off as much copper as possible, then take the wire out of the solution with the stirring rod. Rinse the rest of the copper off with water, and if it doesn't come off, use one or two drops of the HCl solution. Place the Al wire aside.
Step 6
Collect and wash the copper produced in the reaction.
A. Set up a funnel for filtration in the ring stand
B. Place a piece of filter paper into the funnel
C. Pour the copper onto the filtration paper
D. Use water if the copper won't leave the beaker
E. Wash the copper in the paper twice more with water
Step 7
Record the mass of a clean piece of filtration paper. Allow the copper to dry fully. Make sure the copper is dry before transferring it to the clean filtration paper, then record the mass of the paper with the dry copper. Once finished, dispose of the copper, aluminum wire, and the filtered liquid.
Data Table
Data Analysis
Error Discussion
The only error we seemed to have was too many moles of water. We had the correct amount of copper and chlorine, but we seemed to have an extra mole of water. That extra mole of water could have happened because we added a little too much water during the filtration process, but I don't see how that could affect anything. Another possibility is the improper measuring of water. We could've read the scale wrong, or we recorded the wrong mass that was in the original copper chloride hydrate.
.28 g H2O/.18 g H2O (100) = 155% percent yield for H2O
.18 g - .28 g/.18 g (100) = 55% percent error for H2O