Name:___________________________________ Pd.:_____
Lab – Evidence for Chemical Change
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) →
Type of Reaction:
4. __ 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.
