Name:___________________________________ Pd.:_____
One way of knowing that a chemical change has occurred is to observe that the properties of the products are different from those of the reactants. The new product can then become a reactant in another chemical reaction. In this experiment you will observe a sequence of changes that occur when a solution that begins as copper (II) nitrate is treated with a series of different reactants. All of the reactions will take place in the same test tube. At each step you will look for evidence that a new substance is formed as a result of a chemical change. You will also observe heat changes and relate them to chemical reactions.
Pre-Lab
For each reaction: IDENTIFY the type of chemical reaction, PREDICT the products, and
BALANCE the chemical equation.
1. __ Cu(NO
3
)
2
(aq) + __ NaOH (aq) 
Type of Reaction:
2. __ Cu(OH)
2
(s) + heat 
Type of Reaction:
3. __ CuO (s) + __ HCl (aq) 
4.
Type of Reaction:
__ CuCl
2
(aq) + __ Al (s) 
Type of Reaction:
5. __ HCl (aq) + __ Al (s) 
Type of Reaction:
Procedure
1.
Place 50 mL of water into the 100 mL beaker and heat it on a hot plate until boiling. This will be the hot-water bath you will use in step 6.
2.
While the water bath is heating, use the lab marker and ruler to make three marks on the test tube that are 1 cm apart. Make the marks starting at the bottom of the test tube and moving toward the top.
3.
Add 1.0 M Cu(NO
3
)
2
, copper
(II) nitrate, to the first mark on the test tube as in Figure
1.
4.
Add 1.0 M NaOH, sodium hydroxide, up to the second mark on the test tube as in
Figure 2.

5.
Mix the solutions with the stirring rod. Touch the bottom of the outside of the test tube to see if heat is released. The copper-containing product in the test tube is copper (II)
hydroxide. The other product is sodium nitrate.
6.
Put the test tube into the hot-water bath you prepared in step 1. Heat it until no more changes occur. Record the changes that occur in the test tube. The products of this
reaction are copper (II) oxide and water. Hint: If it doesn’t turn Black add a few more drops of NaOH.
7.
Remove the test tube from the hot-water bath. Turn off the hot plate. Cool the test tube and its contents for 2 minutes in room-temperature water.
8.
Add 1.0 M HCl, hydrochloric acid, to the third mark as Figure 3. Mix with the stirring rod.
Remove stirring rod and rinse in tap water. Record the changes that occur in the test tube.
The new products are copper (II) chloride and water.
9.
Place a 12 cm piece of aluminum wire in the test tube. Leave it until no reaction is observed.
Touch the bottom of the test tube to check for temperature change. Record the changes that occur in the test tube. Two reactions take place. Copper (II) chloride and aluminum produce copper and aluminum chloride. The aluminum also reacts with
hydrochloric acid to form hydrogen and aluminum chloride.
10.
Carefully remove the wire from the test tube with your stirring rod. Decant the solution down the drain and flush with water. Compare the copper formed to a sample of copper wire.
Record your observations. Solid copper and aluminum should go in the trash can.
Observations
Reactants Products Evidence of Reaction
Cu(OH)
2
+ NaNO
3
Observation:
Cu(NO
3
)
2
+ NaOH
Observation:
Cu(OH)
2
+ heat
Observation:
CuO + HCl
Observation:
CuCl
2
+ Al
Observation:
HCl + Al
Observation:
CuO + HCl
Observation:
CuCl
2
+ H
2
O
Observation:
Cu + AlCl
Observation:
H
2
+ AlCl
3
3
Observation:

Analysis and Conclusion
1.
List four types of observations that indicate when a chemical change has occurred.
2.
What is the color of solutions of copper compounds?
3.
In what two ways is heat involved in chemical change? Cite specific examples from this experiment.
4.
Write word equations for each of the five reactions that occurred, including states of matter.