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Kinetics and Reaction Rate
141
Kinetics and Reaction Rate— Demonstration Kits, continued
“Visualizing the Transition State” Demonstration Model
By: Jeff Fieberg
Centre College, Danville, KY
Kinetics concepts are by nature abstract. How do you explain to students that the transition state lies at the “top of a potential energy barrier” and is “inherently unstable?” Demonstrate the properties of the transition state or activated complex with this unique, colorful demonstration device—a plastic ball that suddenly switches inside and out when tossed into the air with just the right amount of spin. Simply toss the ball into the air and watch as it inverts and changes color. The magical, color-flipping toy models a chemical reaction in which a reactant must pass through an unstable transition-state configuration before it is converted to a product. Use this novel teaching aid to make learning both meaningful and fun! Concepts: Chemical kinetics, transition state theory, activated complex. Time Required: 10 minutes
Materials Provided: “Switch-Pitch” transition state model.
The Yellow and Blue Switcheroo— Chemical Demonstration Kit
By: Jim and Julie Ealy, Retired
The Peddie School, Hightstown, NJ
Your students will think you are the king or queen of chemistry when you do this amazing demonstration. Three colorless solutions are mixed to produce a yellow solution and then suddenly the solution turns blue, then yellow again, etc. The solution will oscillate between yellow and blue for ten minutes. If you’ve never seen or done an oscillating clock reaction, don’t pass this one up; it’s fit for a king! Demonstration Notes included. Concepts: Oscillating reactions, kinetics.
Time Required: 15 minutes
Chemicals Provided: Hydrogen peroxide solution, acidified potassium iodate solution, and starch-malonic acid-manganese(II) sulfate solution. Note: Perform this demonstration in a fume hood or well-ventilated lab.
See free video at flinnsci.com.
Fluorescent Oscillating Reaction—
Chemical Demonstration Kit
By: Rhonda Reist, Olathe North High School, Olathe, KS
Eerie and incredibly cool! Mix colorless and orange solutions in a beaker and start stirring. The color of the solution changes from orange to green. Dim the lights, switch on a black light and the real show begins! Observe the brilliant, fluorescent orange glow! This unique adaptation of a classic oscillating reaction is due to rising and falling concentrations of ruthenium(II) and (III) complex ions. Use the beauti- ful, radiant color changes to illustrate oxidation states, then sit back and enjoy the show! Demonstration Notes, reproducible student worksheet, and answer key are included.
Concepts: Oscillating reactions, oxidation–reduction reactions, reac- tion mechanisms, kinetics, catalysts.
Time Required: 20 minutes
Materials Provided: Cerium ammonium nitrate and ruthenium chlo- ride acidified solution, malonic acid, potassium bromate, and sulfuric acid solution.
Note: A UV lamp or other black light source is required and available separately.
See free video at flinnsci.com.
“Visualizing the Transition State” Demonstration Model AP7104
Catalog No.
Description
Price/Each
AP7104
“Visualizing the Transition State” Demonstration Model
$15.60
Catalog No.
Description
Price/Each
AP8660
The Yellow and Blue Switcheroo— Chemical Demonstration Kit
$31.05
The Yellow and Blue Switcheroo— Chemical Demonstration Kit AP8660
Catalog No.
Description
Price/Each
AP7245
Fluorescent Oscillating Reaction— Chemical Demonstration Kit
$72.40
AP9030
Ultraviolet Lamp, 18"
45.30
Fluorescent Oscillating Reaction— Chemical Demonstration Kit AP7245