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Flinn Lab Activities and Demonstrations
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Properties of Liquids and Solids— Demonstration Kits, continued
Density Demonstration Bottles
By: Lee Marek, Retired
Naperville North H.S., Naperville, IL
Students will be mesmerized by watching the layers in these bottles move and separate as they are turned upside-down, swirled, and shaken. Begin your discussion on density by displaying one bottle in front of the class. Later in the week, switch the bottles when students are not pres- ent. The next day, see if students notice a change in the layers. Challenge students to offer suggestions for how this event may have occurred. A great critical-thinking demonstration that also introduces concepts such as density and polarity. As a bonus, the bottles may be used again when covering hydrogen bonding and immiscibility. Teacher Demonstration Notes are included. Both bottles may be reused for years.
Concepts: Density, polar/non-polar, immiscibility, hydrogen bonding. Time Required: 10 minutes
Materials Provided: Two bottles, clear and colored oil, colored water.
Hot Wax—Chemical Demonstration Kit
By: The Flinn Staff
Have you ever had melted wax drip on you? It’s hot!
When melted wax solidifies, enough heat may be released to cause severe skin burns. Find out how much heat is released when melted wax solidifies with this three-part demonstration. Measure the temperature of “hot wax” as it cools, graph the cooling curve data to estimate the melting point, and then do a simple calorimetry test to calculate the heat of fusion of paraffin. The idea that a liquid releases heat when it solidifies is not obvious—this economical demonstration will really “solidify” the concept of phase changes and their related energy changes for your students!
Concepts: Phase changes, heat of fusion, calorimetry.
Time Required: 20 minutes
Materials Provided: Paraffin wax, borosilicate test tubes, polystyrene cups, and boiling stones.
Intermolecular Attractions—
Multi-Demonstration Kit
By: Mark Langella
Mahopac High School, Mahopac, NY
Molecules can’t be seen, but we can see the forces between molecules: Use this set of four demonstrations to show students what happens when molecules attract each other—or don’t!
• Floating Oil Droplet—The difference in densities of water and ethyl
alcohol causes an oil droplet to “float” in the middle of a beaker.
• Bubble Shapes—Straws and twist ties are used to create beautiful
geometric bubbles when dipped in a soap solution.
• Capillary Action—Measure and compare the ability of water and
ethyl alcohol to rise in a glass capillary tube.
• Vanishing Volume—What happens to the 5 mL that was lost when 50
mL portions of water and ethyl alcohol are added together?
Use each demonstration separately to illustrate different types of intermolecular forces, or perform them all together for review or assessment.
Concepts: Surface tension, hydrogen bonding, dipole–dipole attrac- tions, cohesive and adhesive forces, London dispersion forces.
Time Required: 30 minutes
Materials Provided: Isopropyl alcohol, ethyl alcohol, dishwashing detergent, glycerin, stirrers, twist ties, disposable pipets, capillary tube, and disposable Petri dishes.
PROPERTIES OF LIQUIDS AND SOLIDS—DEMONSTRATION KITS continued on next page.
Density Demonstration Bottles AP6684
Catalog No.
Description
Price/Each
AP6684
Density Demonstration Bottles
$39.00
K0007
Kerosene, Blue, 500 mL
11.75
Catalog No.
Description
Price/Each
AP6887
Hot Wax—Chemical Demonstration Kit
$21.60
Hot Wax—Chemical Demonstration Kit AP6887
Intermolecular Attractions—Multi-Demonstration Kit AP6928
Catalog No.
Description
Price/Each
AP6928
Intermolecular Attractions—Multi-Demonstration Kit
$54.90