SNC 1D0
Identifying Physical and Chemical Changes
In this activity, you will observe a number of chemical changes. As you classify these
changes, you will identify specific evidence of chemical change.
Purpose
To collect and use evidence to identify chemical changes
Equipment and materials
1. Eye protection
2. 2 test tubes / group
3. Test-tube rack
4. Test-tube stoppers
5. Candle
6. Scoopula
7. Pipette or eye dropper
8. 50 mL beaker of solutions:
a. Dilute hydrochloric acid (0.1 M HCl)
b. Distilled water
c. Dilute sodium hydroxide (0.1M NaOH)
d. Potassium iodide solution (saturated)
e. Lead nitrate solution (saturated)
9. Magnesium ribbon (Mg)
10. Wooden splint
11. Copper(II) sulphate (CuSO4)
12. Steel wool
Procedure
1. Use the data tables provided. You will be required to make your own for the lab
report.
2. Put on your eye protection and keep it on for the duration of lab.
Part A
Change 1
3. Add hydrochloric acid to a test tube to a depth of about 2cm (finger width)
4. Before you add the magnesium ribbon observe and record the properties of both
reactants (acid and magnesium).
5. Add two 1cm strips of magnesium ribbon to the test tube. Place stopper on the
tube. Check for evidence of change occurring inside test tube. Check the bottom
of the test tube with your hand for temperature changes. Record your
observations.
6. Place the test tube in a test tube rack and wait 15sec.
Change 2
7. Light a wood splint from the candle flame (lit by your teacher)
8. Bring the splint close to the mouth of the test tube.
9. Remove the stopper and hold the burning splint near the mouth of the “acid +
magnesium” test tube. Record your observations
10. Dispose of the contents of the test tube into the beaker labelled “waste” on
teacher’s desk
11. Rinse the test tube well with tap water
Part B
Change 3
12. Pour distilled water into a test tube to a depth of about 3cm
13. Before you add copper (II) sulphate observe and record its properties.
14. Add about 2 g of copper (II) sulphate (1 cm of the end of the scoopula) to the test
tube.
15. Stopper and invert the test tube several times to mix its contents well. Record
your observations
Change 4
16. Before you add the steel wool to the above test tube observe and record its
properties.
17. Remove the stopper. Add a small ball of steel wool (about the size of an aspirin
tablet) to the test tube with the copper (II) sulphate solution..
18. Stopper the test tube again and mix well
19. Wait 2 minutes and observe. Record your observations
Change 5
20. Before you start adding sodium hydroxide to the above test tube observe and
record its properties.
21. Remove the stopper. Add about 5 drops of sodium hydroxide to the test tube
using the pipette. Observe and record observations.
22. Slowly add drops of hydrochloric acid to the test tube using a pipette. Gently swirl
the test tube after every couple of drops. Continue adding drop wise until the
solid disappears. Record your observations
23. Before you start adding sodium hydroxide again predict what will happen. Add a
few drops of sodium hydroxide again and observe what happens. Record your
observations
24. Dispose the contents into the waste beaker
25. Rinse the test tubes well with water.
Part C
Change 6
26. Obtain 5 ml of potassium iodide and 5 mL of lead nitrate solutions in separate
test tubes
27. Examine the potassium iodide and lead nitrate solutions and record your
observations
28. Pour 5 mL of potassium iodide into 5 mL of lead nitrate solution
29. Observe what happens
30. Record your observations
Discussion questions: (Analysis of Data)
1. List the 5 indicators to watch for as evidence that a chemical reaction has
occurred.
2. Define precipitate. In which step(s) did you observe the formation of a
precipitate?
3. Define Endothermic and Exothermic. In which step(s) did you observe a change
in temperature? Tell if the changes were endothermic or exothermic.
4. In which step(s) did you observe a color change?
5. In which step(s) did you observe the formation of a gas? Name the gas?
6. In which step(s) did you observe formation of light?
7. Where there any physical changes in this lab? If so where did they occur?
Lab Report format:
12 font, Times new roman
You are to write a lab report with the following sections:
 Cover page: (Your name, Partners name(s), my name, title, date submitted)
2 marks [C]
 Introduction: 5 marks [C]
Maximum 200 words on physical and chemical changes. Evidence for each. In-text
referencing using MLA format. Cite at least 2 references.
 Purpose: 2 marks [C]
1-2 sentence to explain the purpose of this lab
 Observation Charts: 10 marks [C]
Insert your typed up observation table(s), detailing observations for every change.
 Discussion Questions.
Q #1 3 marks [T/I]
Q#2 3 marks [MC]
Q#3 3 marks [MC]
Q#4 1 mark [MC]
Q#5 2 marks [MC]
Q#6 1 mark [MC]
Q#7 3 marks [MC]
Total Lab
/35 (refer to rubric for more detail on each section)
Identifying Chemical Changes
PART A: Change 1
Reactants
Possible Observation Tables
Properties
Reaction Observations Change 2
Hypothesis: ___________________________________________________________
Hydrochloric acid +
magnesium
Products + flame
PART B: Change 3
Reactants
Properties
Reaction Observations
Copper sulphate +
water
Copper sulphate +
iron
+ sodium
hydroxide
+ hydrochloric acid
+ sodium
hydroxide
PART C: Observations
Before mixing
After mixing
potassium iodide + lead nitrate