Types of Chemical Reactions
Purpose:
To observe evidence of chemical change and identify the reactants and
products in a series of chemical reactions. Inferences and observations will lead to the
classification of each reaction type and a balanced formula equation for each reaction.
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. In this series of reactions, the
product of one reaction acts as a reactant in the next. The series of reactions involve
copper II nitrate solution that is treated with different reactants. All of the reactions take
place in the same test tube. At each step, evidence of chemical change, classification of
the reaction type, and a balanced formula equation will be recorded.
Materials:
Goggles
Bunsen burner
Stirring rod
Ring stand
Rings
250 mL beaker
Ruler
Test tube and rack
Wire gauze
Test tube clamp
Marking pen
Reagents:
0.5 M Copper (II) nitrate
1.0 M HCl
0.5 M NaOH
Aluminum foil
Procedure:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Goggles!
Set up a double ring-stand apparatus.
Heat approximately 150 mL of tap water in the 250 mL beaker using the
Bunsen burner and ring-stand set up.
While the water is heating, add 10 mL 0.5 M Cu(NO3)2 to the test tube.
Add 15 mL 0.5 M NaOH to the test tube.
Mix the solutions with a stirring rod.
Touch the outside of the test tube to see if heat was generated as the solutions
mixed.
Record all observations. (color, temperature, state, odor)
The copper containing product in the test tube is copper (II) hydroxide. The
other product is sodium nitrate. Which is the solid?
Put the test tube into the hot water bath using a test tube clamp to support it.
Continue to heat the mixture until no more changes are noticed.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Record all changes observed. The new products of this reaction are copper
(II) oxide and water.
Remove the test tube from the hot water bath. Turn off the burner.
Allow the test tube to cool in a test tube rack.
After the mixture is cooled, add 15 mL of 1.0 M HCl to the test tube.
Record the changes that occur in the test tube. The new products are copper
(II) chloride and water.
Place a piece of aluminum foil into the mixture in the test tube. Leave the foil
in the solution until the reaction is complete.
Touch the bottom of the test tube to check for a change in temperature.
Two reactions have taken place here, Copper (II) chloride and aluminum
reacted to form copper and aluminum chloride. The aluminum also reacted
with the hydrochloric acid to form hydrogen gas and aluminum chloride.
Clean and return all equipment. Dispose of chemicals in waste container and
clean the test tube. Do NOT pour chemicals down the drain.
Wash hands and return goggles.
Data and Observations:
Observations:
Step #8
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Step #11
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Step #15
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Step #17
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Questions:
1.
What are some causes of chemical change?
2.
What are some observed changes that indicate a chemical change is taking
place?
3.
What is the difference between a chemical and physical change?
4.
In the last step, where is the aluminum chloride, and how could it be
recovered?
5.
What is the color of the solutions of copper compounds?
6.
Identify all of the reactants in this series of reactions.
7.
Identify all of the products in this series of reactions.
8.
Why do some substances form a solid in solution?
Write a balanced formula equation and classification type for each of the reactions
observed.
A.
Copper (II) nitrate + sodium hydroxide →
Equation:
Reaction type:__________________
B.
Copper (II) hydroxide + heat →
Equation:
Reaction type:__________________
C.
Copper (II) oxide + hydrochloric acid →
Equation:
Reaction type:__________________
D.
Copper (II) chloride + aluminum →
Equation:
Reaction type:__________________
E.
Hydrochloric acid + aluminum →
Equation:
Reaction type:__________________