Comparing Copper Chloride Lab

Comparing Copper (I) Chloride and Copper (II) Chloride

Objective: To observe and identify the difference between physical and chemical change of two substances. To identify and record the quantitative and qualitative properties of substances before and after a physical or chemical change of copper I, copper II and aluminum.

Pre-Lab Questions:

1. What is the difference between quantitative and qualitative observations?

2. Do you think that the CuCl and CuCl₂ will have the same properties? Why or why not?

Procedure:

1. Weigh 0.25 grams of CuCl powder (green) on electronic balance.

2. Weigh 0.50 grams of CuCl₂ (blue green) crystal on electronic balance.

3. Using a graduated cylinder, measure 50 mL of water, pour into beaker, do this twice once for each beaker.

4. Record the temperature of the water in each beaker.

5. Pour the CuCl into a small beaker.

6. Stir to dissolve all of the CuCl and record new temperature.

7. Pour the CuCl₂ into a big beaker.

8. Stir to dissolve all of the CuCl₂ and record new temperature.

9. Take a piece of aluminum foil and add it to each solution. Observe for a few minutes and record a second temperature.

10. While you are performing steps, record your observation of qualitative and quantitative observations.

Qualitative observations:

CuCl:                                                          CuCl₂:

1.                                                                1.

2.                                                                2.

3.                                                                3.

Quantitative observations:  

CuCl temperature:                                     CuCl₂ temperature:

H₂O Before:                                               H₂O Before:

Dissolving:                                                 Dissolving:

After aluminum:                                        After Al:

Post-lab Questions:

1. What are the charges for copper in CuCl and CuCl₂? What does this change in the formula for each of the compounds?

2. Which reaction had the greatest change in temperature? Was there a connection to which solution reacted more with aluminum and its temperature?

3. Identify any chemical changes in your experiment and explain why it is a chemical change. Make sure to explain your evidence why it is a chemical change.