Chem 11 Types of Chemical Reactions
Purpose: To study different types of chemical reactions.
Apparatus:
Bunsen burner test tubes (4) test tube holder test tube clamp
100 mL beaker test tube rack ring stand pippette
Materials:
wood splints potassium iodide solution lead II nitrate solution
hydrochloric acid mossy zinc manganese dioxide
hydrogen peroxide copper(II) sulfate pentahydrate crystals
aluminum foil copper(II) chloride
Observations: Draw a table to record observations for each reaction.
Procedure:
A. Using a scoopula, obtain a small amount of copper II sulfate pentahydrate (CuSO4∙5H2O) crystals in a clean dry test tube. Set up the ring stand and secure the test tube in the test tube clamp (on a slight angle, facing away from others). Gently heat with a Bunsen burner. (1) What do you observe on the upper part of the test tube? (2) What do you observe in the bottom of the test tube? Continue to heat until no further change is observed.
Allow the test tube to cool, and add 5 drops of water. (3) What do you observe? (4) What is the substance remaining in the tube after heating?
B. Place 10 drops of lead II nitrate solution in a test tube. Add 5 drops of potassium iodide. (5) What do you observe? (6) If one of the products is potassium nitrate (which is soluble in water), what is the other product?
C. Place a small piece of mossy zinc in a test tube. Add enough hydrochloric acid (HCl) to just cover the zinc (about 2-3mls). (7) What do you observe?
D. Place 3mL of hydrogen peroxide in a test tube. Using the tip of the scoopula, add a tiny amount of manganese dioxide. (8) What do you observe? Hold a glowing splint in the mouth of the test tube and then lower it down further into the test tube. Do not drop it in. (9) What do you observe? The manganese dioxide is a catalyst and water is one product of this reaction. (10) What is the other product of this reaction?
E. Fold a piece of aluminum foil into a narrow strip and place in the 100ml beaker. Add enough copper(II) chloride solution to just cover the aluminum (about 3-4mls) . (11) What do you observe?
F. DEMO: Electrolysis of water. (12) What do you observe?
Analysis:
1. Answer the questions in the procedure.
2. Identify each of the types of reactions.
3. Write a word equation AND a balanced chemical equation for each of the reactions.
4. No combination reactions were described in the procedure section. Give an example of a combination reaction and write a balanced equation for it.
5. Although no combustion reactions were described in the procedure, one combustion did occur. What was the reaction? Write a balanced equation for it.
Conclusion: Describe the evidence you used to identify each of the types of reactions.
*Extension: Make up new chemical reactions using the list of chemicals above. Write them down. Once approved, perform the reactions and record observations.