Chem I Lab
Chemical vs. Physical Change
Name________________________ Period______
Objective
1. Utilize proper qualitative and quantitative observation techniques.
2. Conduct reactions between CuCl2 (copper chloride) solution + Al(s) (aluminum), and
Ba(OH)2(s) (barium hydroxide) + NH4Cl(s) (ammonium chloride)
3. Differentiate between chemical and physical properties and changes of matter.
4. Differentiate between exothermic and endothermic reactions.
Background
Research and define the following:
 qualitative observations
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quantitative observations
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physical change
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chemical change
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exothermic reaction

endothermic reaction
Temperature conversions:
°C + 273 = K
K – 273 =° C
°C = (°F -32)÷1.8
°F =(°C x 1.8) +32
Hypothesis:
Part I: A reaction between CuCl2 solution + Al(s) is reported to produce a gas and precipitate. Do
you think that it would be an endothermic or exothermic reaction?
Part II: A reaction between Ba(OH)2(s) + NH4Cl(s) is reported to produce a gas and a liquid. Do you
think that it would be an endothermic or exothermic reaction?
Safety:
Heating safety, glassware safety, eye safety, chemical safety, proper waste disposal
Materials:
Safety goggles
Copper (II) Chloride
Beaker
Aluminum foil
1 thermometer
Ammonium chloride
1 stirring rod
Barium hydroxide
Spoon
Test tube
25 mL graduated cylinder
Test tube rack
Magnifying glass
Pre-lab Questions:
1. Convert 16°C into °F (show work).
2. List 4 indications that aid in identifying if a chemical change has occurred.
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3. How does physical change differ from chemical change?
1.
Classify substances as heterogeneous/homogeneous mixtures or elements/compounds:
Aluminum foil
Copper(II) chloride
Copper(II) chloride solution
Barium hydroxide
Water
Procedures
Experiment 1:
1. Obtain one level spoon full of the substance labeled Copper (II) Chloride at front table.
*Be cautious when taking it to your lab station.
1. Describe at 3 physical properties of the copper (II) chloride, and record these into Data Table 1A.
*Be creative – use equipment to help make these observations.
2. Measure 25 mL of distilled water using your graduated cylinder.
3. Pour water into beaker, and then carefully pour the copper (II)chloride into the beaker. Record at least
3-4 observations into Data Table 1A before you stir the contents.
*Make observations of the crystals and the water separately because you have two states of matter
represented
4. Using the glass stirring rod, stir the mixture until the copper (II) chloride is completely dissolved.
*Caution: do not look or smell directly above the beaker. Look off to the side.
5. Record 2 more observations into Data Table 1A after you stirred.
6. Obtain an initial temperature of this mixture and record in Data Table 1B.
7. Keep the thermometer in the beaker, and carefully place a loosely crumpled ball of aluminum foil into
your beaker. Immediately record 3 observations into Data Table 1A.
8. Stir gently and record temperature readings every 15 seconds for 3 minutes in Data Table 1B. Record
additional observations in Data Table 1A. *Stir the mixture occasionally while making observations.
9. Convert the initial temperature, the temp after 15 seconds and the final temperature from °C to °F and
record in Data Table 1C. *SHOW YOUR CALCULATIONS (3 of them) IN CALCULATION BOX on page 4.
SEE NEXT PAGE FOR CLEAN UP 
Clean up for Part 1:
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Use the spoons and tweezers to scrape out the waste solid into the beaker labeled WASTE SOLID.
Using your stirring rod pour the waste liquid in the beaker labeled WASTE SOLUTION.
DO NOT POUR THESE DOWN THE SINK, when your beaker is clean enough – go to a sink and wash
with brush and soap.
Clean all other all other equipment with soap and water, dry and put back at your station (stirring rod,
thermometer, etc.)
Wash hands
Data Table 1A
Observations
Data Table 1B
Temperature °C (begin
recordings after adding Al)
Dry crystal
 _____________________
 _____________________
 _____________________
Data Table 1C
Temperature in °F (after
converting from °C)
Initial temp ̊C
15 sec
30 sec
XXXXXXXXXXXXXXXXXXX
45 sec
XXXXXXXXXXXXXXXXXXX
1.00 min
XXXXXXXXXXXXXXXXXXX
1.15 min
XXXXXXXXXXXXXXXXXXX
After stirring
 _____________________
 _____________________
1.30 min
XXXXXXXXXXXXXXXXXXX
1.45 min
XXXXXXXXXXXXXXXXXXX
Immediately after adding Al
 _____________________
 _____________________
2.00 min
XXXXXXXXXXXXXXXXXXX
2.15 min
XXXXXXXXXXXXXXXXXXX
During
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2.30 min
XXXXXXXXXXXXXXXXXXX
2.45 min
XXXXXXXXXXXXXXXXXXX
Crystals in water
 _____________________
 _____________________
 _____________________
temp recordings
_____________________
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Final temp
3.00 min
Procedures
Experiment 2:
1.
2.
3.
4.
5.
Obtain approximately 2.00 g of Barium hydroxide using the weighing paper.
Obtain 1.50 g of ammonium chloride using weigh paper. Take to your station.
Use magnifying glass to help record 3 observations of each in Data Table 2A.
Pour the Barium hydroxide into the test tube.
Immediately place thermometer into the test tube of barium hydroxide, and measure the initial
temperature – record in Data Table 2B.
6. Pour the Ammonium chloride into the test tube of Barium hydroxide. Make observations and record in
Data Table 2A. *Be aware of smell !!! Use wafting technique for observation.
7. Carefully use the thermometer to stir the solids together.
8. Record additional temperatures every 15 seconds for 3 minutes. Record in Data Table 2B.
*The more you mix the chemicals, the better the reaction.
9. Continue to record additional observations and record in Data Table 2A.
10. Convert the initial temperature, the temp after 15 seconds and the final temperature from °C to °F and
record in Data Table 2C. *SHOW YOUR CALCULATIONS (3 of them) IN CALCULATION BOX on page 4.
SEE NEXT PAGE FOR CLEAN UP 
Clean up for Part 2:
 The contents of both test tubes can be rinsed out with water and flushed down the drain with
excess (running) water.
 Wipe all equipment down
 Clean counter with spray
 Teacher will come to check your station.
Data Table 2A
Observations
Data Table 2B
Temperature °C (begin
recordings after adding Al)
Initial (Dry Barium Hydroxide)
 _____________________
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Initial (Dry Ammonium Chloride)
 _____________________
 _____________________
 _____________________
When Mixed
 _____________________
 _____________________
 _____________________
During
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temp recordings
_____________________
_____________________
_____________________
Data Table 2C
Temperature in °F (after
converting from °C)
Initial temp ̊C
15 sec
30 sec
XXXXXXXXXXXXXXXXXXX
45 sec
XXXXXXXXXXXXXXXXXXX
1.00 min
XXXXXXXXXXXXXXXXXXX
1.15 min
XXXXXXXXXXXXXXXXXXX
1.30 min
XXXXXXXXXXXXXXXXXXX
1.45 min
XXXXXXXXXXXXXXXXXXX
2.00 min
XXXXXXXXXXXXXXXXXXX
2.15 min
XXXXXXXXXXXXXXXXXXX
2.30 min
XXXXXXXXXXXXXXXXXXX
2.45 min
XXXXXXXXXXXXXXXXXXX
Final temp
3.00 min
Calculations:
For both reactions, show the temperature change in degrees Fahrenheit.
(hint... change from OC to OF, then subtract the initial temp from the final temp)
Calculations – Part 1
Calculation – Part 2
Analysis:
1. Construct a line graph and plot BOTH temperature recordings (temperature recordings from
experiment 1 & experiment 2) on the graph below. Be sure to label the axis with variables and
units. Use different colors and provide a key for your lines. Provide a specific title as well!
TITLE: ______________________________________________________________________
2. Make a list of 6 qualitative observations seen in the two reactions.
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3. Provide 2 quantitative observations used in the lab, including units.
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4. List 4 physical changes that occurred in the reactions with a description for each change.
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5. List 5 chemical changes that occurred in the reactions with a description for each change.
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Conclusion:
The conclusion is the most important part of a lab report because it provides those people who are interested
in your study with a quick, concise summary of your procedures and results. A good conclusion, (and yours will be good),
includes the following:
1.
2.
3.
4.
Summarize main lab equipment and chemicals.
Restate hypothesis and whether you support or reject.
Provide data (both observation and measurement) to support your position on your hypothesis.
Overall confidence in the lab. What you did well or what you can improve.
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