In any chemical reaction _________ is neither created nor destroyed. This statement refers to The
____ of __________ of _________. In every chemical reaction there are ________, which are the
substances which start the reaction and _________, which is what is produced after the reaction.
In the demo of the alka seltzer and balloon what was:
Before
The mass of the balloon before the reaction
_________g
The mass of the alka seltzer tablet before the
reaction ______g
The mass of the water before the reaction
______g
The mass of the test tube before the reaction
______g
Total mass of reactants _____g
After
The mass of the balloon after the reaction____g
The mass of the alka seltzer after the
reaction____g
The mass of the water after the reaction _____g
The mass of the test tube after the reaction ____g
Total mass of products______g
Questions:
1. What do you notice about the mass before and after the reaction?
2. What can be considered experimental error in this lab?
3. Write a paragraph on how this activity supports the Law of Conservation.
Part II: What will copper chloride do to a piece of aluminum?
Objective: To observe and decide if a chemical or physical reaction occurred.
Materials: Safety- goggles and apron must be worn. CuCl2 is poisonous.
1 100ml graduated cylinder
copper (II) chloride(CuCl2)
water
Ruler
stir rod
1-250ml beaker
Aluminum foil
balance
scoopula
Scissors
paper towel
forceps
Hypothesis: Make an educated guess on what you think will happen when the Al foil is added to the
water? To the mixture of water and CuCl2? Write your hypothesis in 3rd person, starting with “The
hypothesis is________________________________________________________________________
___________________________________________________________________________________
Procedures:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Make a chart to record observations of the following
Mass of beaker with water
Mass of CuCl2
Mass of Al foil
Observation of water and Al foil
Observations of water and CuCl2
Observation of water, CuCl2 and Al foil
Mass of beaker with water, CuCl2 and Al foil
Measure 30mL of water with graduated cylinder
Pour water into 250ml beaker
Record mass of water in beaker
Measure 3g of CuCl2 by placing a piece of paper on the balance, zero balance out then add
CuCl2. Record mass. Place to side.
Measure a 10cm by 10cm piece of Al foil. Cut and measure and record mass.
Lightly crumble Al foil and place into the water. Record observations.
Remove Al foil from water and place to the side.
Add the CuCl2 to the water and use stir rod to mix. Record observation.
Add the Al foil to the CuCl2 and water. Record observations.
When complete place Al foil, water, beaker and CuCl2 mixture on balance and record mass.
Clean up by pouring mixture into waste container under the fume hood. Rinse beaker and wipe
down stations.
Analysis:
1.
2.
3.
4.
What did the CuCl2 do to the Al foil?
Was this a chemical or physical change? Defend your answer.
Did your observations support or refute your hypothesis? Why?
How did this lab relate to the Law of Conservation of Mass?
Conclusion: (write all sentences in 3rd person)
The hypothesis was
_____________________________________________________________________________________
____________________________________________________________________________________.
The hypothesis was accepted or rejected?_________________________________________________.
The hypothesis was accepted or rejected because according to the data _________________________
_____________________________________________________________________________________
_____________________________________________________________________________________
_____________________________________________________________________________________