CLASS SET
Chemical changes
Purpose: To contrast the properties of two elements, iron and sulfur, with a new
substance made from those elements.
In this lab we will investigate three questions:
1. How are the properties of individual elements affected when those elements
are combined in a mixture?
2. How do the properties of elements change when they form a compound?
3. Is there a difference between a mixture of two elements and a compound
formed from those same two elements? If there is a difference, what causes it?
Materials:
Triple-Beam Balance
Matches
Test-Tube
2 (½ sheets) white paper
Procedures:
Forceps
Spoon
Sulfur Powder Iron Powder
Beaker
Magnet
Test Tube Clamp
Bunsen Burner
Hand Lens
Safety Goggles
Timer
Before doing any part of the following activities, put on your safety goggles.
KEEP them on for the duration of the activity.
For each step, record all of your observations in the data table.
1. Place paper on triple beam balance. Measure 4g of sulfur powder.
2. Use your hand lens to observe the color, particle size, and shape of the sulfur.
Record your observations in your data table.
3. One scientist should carefully hold the paper containing the sulfur powder while
another scientist moves the magnet under the paper to see if the magnet
has any effect on the sulfur. Record your observations on the data table.
Carefully set aside sulfur.
4. Place another sheet of paper on the triple beam balance. Measure out 7g of
iron powder.
5. Use your hand lens to observe the color, particle size, and shape of the iron
powder. Record your observations on the data table.
DO NOT PUT THE MAGNET INTO THE IRON POWDER.
6. Very carefully, have one scientist hold the paper while another moves the
magnet UNDER THE PAPER to see if the magnet has an effect on the iron.
7. Mix the iron and sulfur together on one piece of paper. Use the back of your
spoon to stir/pack down the mixture until it is uniform throughout. Use the hand
lens to observe the color, shape, and size of the particles. Next test the mixture
to see if it is magnetic by moving the magnet under the paper. Record your
observations.
8. Fill your beaker halfway with cold water.
9. Carefully pour the iron/sulfur combination into your test tube.
10. Light the Bunsen burner.
11. Using your test tube clamp, heat the test tube over the flame. Make sure to
point the mouth of the test tube away from you (and others). Heat the
mixture for about 4-5 minutes. Move the test tube around in the flame so that all
of the contents are evenly heated. Take careful observations.
12. After 4-5 minutes, or when you see no further changes occurring in the test
tube, shut off the burner. Immediately put the test tube into the beaker of
water. The test tube should break at the bottom. If it does not, raise your hand.
13. Using the forceps, hand lens, and magnet examine the new substance.
Record your observations.
Name_____________________________________________ Period_______
PYRITE LAB
Data Table
Physical
Properties
Sulfur
Iron
Iron-Sulfur
Combination
Before Heat
Iron-Sulfur
Combination
After Heat
Color
Shape of
Particles
Size of
Particles
Effect of
Magnet
Observations
(What happened
when the Sulfur and
Iron were heated—
Be Specific!)
1.
Analysis and Conclusions
Compare the properties of the sulfur alone with the iron-sulfur combination (before heat).
2. Compare the properties of the iron alone with the iron-sulfur combination (before heat).
3. When you combined the iron and sulfur did you create a mixture or a compound?
How do you know?
4. How did heating the iron and sulfur affect them?
5. How did the properties of the iron-sulfur combination change after it was heated?
(Particle size, Magnetism, Color) Compare the new substance to both the sulfur alone and the iron
alone. What changed?
6. Did a chemical change occur? Use your observations to justify your response (what did you see
happen, why is it important?)
7. Why was it necessary to heat the test tube?
8. The compound you have formed is called Iron Sulfide. Sometimes it is called Pyrite or fool’s gold.
The chemical equation for the reaction is: Fe + S2  FeS2
Is this equation balanced? Show your work.
9. The element sodium reacts explosively with water, and the element chlorine is a yellowish-green
poisonous gas. When they are chemically combined they form nonexplosive, nonpoisonous table
salt. Explain how this is possible.
10. What is the Law of Conservation of Mass?
11. According to the Law of Conservation of Mass, if you begin your experiment with 4g of Sulfur
and 7g of Iron (your reactants) what will the mass of your product be? (Show your work)
12. Was this experiment an example of an exothermic or an endothermic reaction?
Explain your reasoning.
13. Identify each as an element, mixture, or compound.
a.
b.
c.
d.
e.
f.
Aluminum foil______________________
Air_____________________________
Water__________________________
Salt water_______________________
Copper wire______________________
Steel___________________________
14. Identify each as a physical or chemical change
a.
b.
c.
d.
e.
Dissolving salt in water______________________
Melting ice_______________________________
Burning coal______________________________
Rusting__________________________________
Dry ice sublimating_________________________