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Flinn Lab Activities and Demonstrations
1-800-452-1261
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Acids, Bases and Indicators— Demonstration Kits, continued
The Two-Cent Colorful
Chemical Demonstration Kit
By: Pat Funk
Watkins Memorial H.S., Patalaska, OH
The demo with a surprise ending! Two copper pennies are dissolved in nitric acid, producing a green solution. As the pennies dissolve, the NO2 gas produced is bubbled through a (blue) basic solution containing universal indicator. As the NO2 gas dissolves in the solution, it reacts with water to form nitric acid. The colors will span the spectrum from blue to pink as the solution becomes more acidic. As if that weren’t enough color change, wait until you see the finale! (We won’t spoil it.) Concepts: Acid–base indicators, oxidation–reduction, reactions of metals and acids.
Time Required: 25 minutes
Materials Provided: Nitric acid, universal indicator solution, glass tubing (to make glass elbows), stoppers, and plastic tubing.
Note: Pennies are needed, but not provided. Perform this demonstration in a fume hood or well-ventilated lab.
Water to Grape Juice to Milk—
Chemical Demonstration Kit
By: The Flinn Staff
Pour water into an “empty” glass and watch as it turns into purple grape juice. Continue pouring from glass to glass and you’ll serve up some lemonade, a fizzy soda, then milk and finally Pepto-Bismol®. Is it magic—or simply chemistry? This fascinating demonstration allows you to tell a creative story or just “get to the chemistry of it” with the acid–base and precipitation reactions occurring in the glasses. Demonstration Notes included.
Concepts: Acids and bases, solubility, precipitates.
Time Required: 20 minutes
Materials Provided: Sodium bicarbonate, solutions of barium nitrate, phenolphthalein indicator, sodium hydroxide, sulfuric acid.
See free video at flinnsci.com.
Blinking Holiday Colors—
Chemical Demonstration Kit
By: The Flinn Staff
Two solutions of holiday red and green are poured into separate tall form beakers and stirred. After 30 seconds, the beakers magically swap colors, red to green and green to red! Each solution contains a unique mixture of indicators. At low pH, one mixture is red, the other green. At high pH, the red indicator turns green and the green switches to red. The key to the blinking holiday colors is a clock reaction. Each solution starts out slightly acidic and buffered. When one reactant is completely consumed, the pH rapidly increases and the holiday colors rapidly reverse. Holiday fun at an excellent price!
Concepts: Buffers, pH indicators, clock reactions.
Time Required: 10 minutes
Materials Provided: Formaldehyde solution, sodium sulfite, sodium bisulfite, green-to-red indicator solution, red-to-green indicator solution.
The Two-Cent Colorful Chemical Demonstration Kit AP8989
Catalog No.
Description
Price/Each
AP8989
The Two-Cent Colorful Chemical Demonstration Kit
$58.70
Water to Grape Juice to Milk— Chemical Demonstration Kit AP4867
Catalog No.
Description
Price/Each
AP4867
Water to Grape Juice to Milk— Chemical Demonstration Kit
$26.90
Blinking Holiday Colors— Chemical Demonstration Kit AP6858
Catalog No.
Description
Price/Each
AP6858
Blinking Holiday Colors— Chemical Demonstration Kit
$24.90