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Flinn Lab Activities and Demonstrations
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Gases and the Gas Laws—Demonstration Kits,
continued
Diffusion of Gases—Kinetic Energy
Demonstration Kit
By: The Flinn Staff
Molecules are moving! What proof is there for this incredible statement, and what factors influence the kinetic energy of moving molecules? Demonstrate the motion of invisible ammonia and hydrochloric acid gas molecules by their colorful reactions with acid–base indicators. Then compare the rates of diffusion of different size molecules by reacting the two gases together in the ammonium chloride “ring test.” Finally, show the effect of temperature and use the teaching analogy provided with the kit instructions to illustrate the relationship between temperature and kinetic energy. Large, 14 mm x 30 cm glass demon- stration tubes are a perfect size for viewing by all students.
Concepts: Diffusion, kinetic-molecular theory.
Time Required: 15 minutes
Materials Provided: Ammonium hydroxide, hydrochloric acid, phenolphthalein, thymol blue, Beral pipets, cotton balls, two glass diffusion tubes, medicine droppers, rubber stoppers.
Note: Perform this demonstration in a fume hood or well-ventilated lab.
Catalog No.
Description
Price/Each
AP6630
Diffusion of Gases—Kinetic Energy Demonstration Kit
$45.95
Seeing the Invisible—
Chemical Demonstration Kit
By: Jesse Bernstein,
Miami Country Day School, Miami, FL
Is it possible to pour a gas? Set up the specially designed ramp with equally spaced candles. Add a clear liquid to the beaker, hold the beaker at the top of the ramp, and pour the invisible contents. One by one the candles are snuffed out! The beaker contains sodium bicar- bonate. Add vinegar to the beaker and carbon dioxide is produced. Carbon dioxide is denser than air and therefore the carbon dioxide flows down the ramp, displacing the air above each candle and extin- guishes the flame. A dramatic demo showing the fluid nature of gases. Demonstration Notes included.
Concepts: Buoyancy, gas density.
Time Required: 15 minutes
Materials Provided: Sodium bicarbonate, vinegar, plastic ramp, and tea candles.
Pressure vs. Temperature
Gas Law Apparatus
Demonstrate the relationship between the pressure
and temperature of a gas, and accurately determine the value of abso- lute zero, with this innovative gas law apparatus. Apparatus consists of a Mason pressure flask fitted with a special stopper to ensure an air-tight fit, dual-scale pressure gauge, syringe with Luer-lock fitting, and Luer-lock adapters and stopcocks. Simply trap air in the flask at atmospheric pressure, add additional gas via the syringe, cool the flask in an ice-bath, and then begin slow heating, followed by reverse cool- ing, to obtain temperature and pressure measurements. Graph the data and extrapolate backwards to determine absolute zero—students will be amazed at the linear fit and the accuracy of the results! Apparatus is completely reusable, a great value!
A digital thermometer is required and available separately.
GASES AND THE GAS LAWS—DEMONSTRATION KITS continued on next page.
Seeing the Invisible—Chemical Demonstration Kit AP7046
Pressure vs. Temperature Gas Law Apparatus AP7159
Diffusion of Gases—Kinetic Energy Demonstration Kit AP6630
Catalog No.
Description
Price/Each
AP7046
Seeing the Invisible—Chemical Demonstration Kit
$36.60
Catalog No.
Description
Price/Each
AP7159
Pressure vs. Temperature Gas Law Apparatus
$92.15
AP6049
Flinn Digital Pocket Thermometer, Economy Choice
29.30