Stage 1 Desired Results

Graduate Fellows in K-12 Education

Lesson Title: Chemistry Magic ShowDiscipline Focus: ChemistryGrade level: 11th 12th GradeLength of lesson: Multiple class periods

Stage 1 Desired Results

Academic and Content Standard(s):National Science Education Standards: Physical Science B.2 Structure and properties of matterPhysical Science - B.3 Chemical reactions

Minnesota Academic Standards for Science 2009:Physical Science-Matter-Properties and structure of matterPhysical Science-Matter-Changes in matter

Understanding (s)/goals:

Students will understand: Forms of matter such as gases, solutions, acids, bases, indicators, salts, alcohols, etc. and their properties. Reactions such as oxidation and reduction, ionic, acid-base, etc. Electrolysis Osmosis Chemiluminescence

Essential Question(s): What kinds of chemical reactions can we observe in our everyday lives? What common household items can be used in chemical experiments?

Student objectives (outcomes):Students will be able to:

Use proper safety procedures to perform chemistry experiments. Explain the chemical reactions behind the magic.

Stage 2 Assessment Evidence

Performance Task(s):

Students will observe demonstrations and perform chemical experiments.

Other Evidence:

Stage 3 Learning Plan

Learning Activities:

Materials and Resources:The Magical HandStarch solution 500 mL beaker Iodine solution Vitamin C solution or crushed tablet

Battery Blue3 beakers 2 g ascorbic acidwater 2 g potassium iodidestirring rod 10 ml 3 M sulfuric acidd1-9V battery 5 ml starch solutioncloth with Congo red indicator 30 ml 6 M NaOHPick a DrinkFerric Chloride solution3- 50 mL BeakersAmmonium Thiocyanate solution1- 250 mL BeakerTannic Acid solutionGraduated CylinderOxalic Acid solution6 drinking glasses

Lemon Shell GameWaterknife0.1 M sodium hydroxide (NaOH)50 mL beakerPhenolphthaleinsyringe with no tip or plastic tip3 lemons

Solid Water2- 400 mL beakersTable saltSodium polyacrylate WaterFood coloringStirring rod

Vitamin C Clock ReactionTincture of iodine - (2%) (I2)Liquid laundry starch Hydrogen peroxide - (3%) (H2O2) Distilled water 500 mg Vitamin C tablet (C6H8O6) 2 - 250 mL beakers25 mL graduated cylinder 100 mL graduated cylinderLight Box

LuminolDistilled water Glass funnel2 1-L beakers of flasks.0.2g luminal (3-aminophthalhydrazide)Ring stand, ring, and 6-8 clamps 24.0 g sodium bicarbonate (NaHCO3)2 m transparent tygon tubing 0.5 g ammonium carbonate monohydrate1 L Erlenmeyer flask 4.0 g anhydrous sodium carbonate (Na2CO3)2- 100 ml beakers50 ml 3% hydrogen peroxide (H2O2)0.4 g copper (II) sulfate pentahydrate (CuSO4*5H2O)

Alka Seltzer and Gas SolubilityAlka-seltzer tabletsIce bath1 M sodium hydroxide (5 ml)Bromothymol blue indicator, (0.04%, 10 ml)3-250ml beakersStirring rod2 thin stem beral pipets3 large test tubes & rackHot plateThermometer

Thionin: The Two-Faced SolutionIron(II)sulfate (2.0g)Large beaker or fish bowl1M sulfuric acid (100ml)Overhead projector.001 M thionin solution (10ml)Aluminum foil/black construction paperDistilled water (500ml)

Milk of MagnesiaMilk of magnesia (20ml)1 L beaker3M HCl (20ml)Magnetic stir plate and stir barUniversal indicator (4-5ml)Crushed ice and water (780ml)

Glycerin Soap Bubbles/Kid in a BubbleDish soap (Dawn or Joy)1 L beakerGlycerinLarge plastic swimming poolDistilled waterBubble wand (hula hoop with PVC pipe)

Hydrogen BubblesGlycerin soap bubble mixture1L Plastic pop bottle with nose cut off1M H2SO4Ring stand and clamp1 teaspoon Mg(s)Bucket of water500 ml Erlenmeyer flask with spindle tube Two-holed stopper

Rainbow Reaction0.1 M HCLLarge graduated cylinder (1 L)Saturated Na2CO3 solutionBeral pipetsUniversal indicator

NitrocelluloseCotton ballsIce bathConcentrated nitric acid (HNO3)250 ml beaker and watch glassConcentrated sulfuric acid (H2SO4)Stirring rod and Bunsen burner

Burning Water/Burning MoneyWater500 ml beakerLighter fluidDollar bill50% ethanol solution Matches and tongs1 L Erlenmeyer flask

Flaming Salts7 evaporating dishesTongs and matchesMethanolNaCl, BaCl2, CuCl2, LiCl2, SrCl2, KCl, FeCl2

Introductory Activities:Introduce the chemistry magic show activities.Developmental Activities: Perform the chemistry magic show activities.

Closing Activities: Discuss the results of the chemistry magic show activities.

The Magical HandConcept: By adding starch to an iodine solution, the liquid will turn from a light yellow/brown color to a dark blue.Materials: Starch solution Iodine solution 500 mL beaker Vitamin C solution or crushed tablet Procedure:*This demonstration works by using iodine to turn the color of the solution dark blue when starch is added. This demonstration suggests using your hand, but this is only advised if you wear a glove. It is YOUR job to think of a creative magical object to use, or a captivating story to use about a magical cloth. You will need two of the objects so one is normal and one is magical.

1. Put one dropper full of Iodine solution into the beaker. Add approximately 300 ml water (just enough to turn the water a light yellow color). Just before the show, dip one of your objects in the starch solution.

2. With the object without starch on it show the audience that the object isn't magical by placing it into the Iodine water and stir.

3. Then place the object with the starch solution on it into the beaker and stir it around. This should make the solution turn from the light brown to a dark blue.4. Add one dropper full of Vitamin C solution directly into the beaker, or put it on your magical object and use the object to stir it around - this may take about 30 seconds, but the solution should turn back to light yellow again. Alternatively, you can use a mortar and pestal to crush a vitamin C tablet and add the powder to the solution.Explanation:The iodine in the water solution is the yellow color. I had dipped my object into a starch solution before putting it in the iodine solution. The starch is an indicator for the iodine. When both are present, the solution turns a deep blue color. The starch is used to enhance the color of the iodine and also helps to detect if iodine is present. Starch is a long polymer molecule in one shape of a coil - like the spring on a spiral notebook. The iodine molecules go inside of the coil and this is what makes it turn blue. Iodine is a diatomic molecule with the formula, I2.The vitamin C chemical gives an electron to each of the iodine atoms to form the iodide ion with a negative charge. This then shows that the iodide ion is colorless in water solution even in the presence of the starch. This reaction changes the form of the iodine element to the iodide ions.Waste Disposal: This solution is completely safe for the water and disposal down the sink.

Battery Blue Concept: Oxidation and Reduction, Electrolysis, Acids and Base IndicatorsElectrical energy can be used to produce a chemical change.Materials: 3 beakers 2 g ascorbic acid water 2 g potassium iodide stirring rod 10 ml 3 M sulfuric acidd 1-9V battery 5 ml starch solution cloth with Congo red indicator 30 ml 6 M NaOHDirections:Set-up:1. Beaker 1: Fill the first beaker with 600 mL of water. Add the solid potassium iodide (2 grams) to the beaker and stir until dissolved. Add 10 mL 3 M sulfuric acid.2. Measure 1.5 ml Starch solution in a graduated cylinder. 3. Beaker 2: Place 2 g solid ascorbic acid or several ml Ascorbic acid solution to the second beaker (you will need to test this to find an appropriate volume).4. Beaker 3: Fill the third beaker with 500 mL of water and 30 mL of 6 M NaOH.Experiment:5. Add starch to Beaker 1. Nothing should happen.act disappointed.6. Add the battery, solution should turn black/blue in color.7. When Beaker 1 has turned black/blue in color, pour into Beaker 2, solution should turn colorless.8. Soak the red cloth in Beaker 2 and it should turn blue.9. Soak the cloth in Beaker 3 and it should all be red again.Explanation:The first part of the demonstration is in reality an electrolysis reaction with the battery supplying the electrons for the chemical reactions.These are the electrode reactions:Cathode: 2 H2O + 2 e- ====> H2 + OH-At the cathode the battery supplies electrons to water to make hydrogen gas seen as tiny bubbles in the reaction.Anode: 2 I- ====> I2 + 2 e-At the anode, the iodide ion is converted to iodine element and gives away two electrons.The iodine element reacts with the starch that is present to produce the blue color.Iodine, I2 + starch ===> blue-black colorAs the blue starch/iodine solution is dumped into the second beaker which contains ascorbic acid, Vitamin C, another redox reaction occurs to change the iodine element back into colorless iodide ions. Therefore the blue color with the starch disappears. The second series of reactions are not redox but acid/base. The red cloth is dyed with Congo red acid/base indicator. The original solution contains sulfuric acid which changes the Congo red to a blue color. Finally the third beaker contains sodium hydroxide, a base, which changes the Congo red indicator back to red color.

Safety Precautions: Take care in avoiding the spilling of either the sulfuric acid or the NaOH base on your hands, eyes, face as they can cause burns.

Waste Disposal: Dispose all liquids down the drain. The battery can be saved for several more uses.

Pick a DrinkScientific Concept: Iron ions are present in all of the solutions throughout the experiment. Depending on what chemical the iron ions react with will depend on the color change of the water.Materials:Ferric Chloride solution3- 50 mL BeakersAmmonium Thiocyanate solution1- 250 mL BeakerTannic Acid solutionGraduated CylinderOxalic Acid solution6 drinking glassesDemonstration Preparation:1. Line up six drinking glasses in a row. Label them 1-5.2. Place 15 drops of the ferric chloride solution into beaker #1.3. Place 1 drop of the ammonium thiocyanate solution into beaker #2 and 6 drops into beaker #3.4. Place 6 drops of the tannic acid solution into beaker #4.5. Measure 10 mL of the oxalic acid solution with a graduated cylinder and place it in beaker #5.6. Fill your last glass with 300 mL of water, label it beaker #6.Demonstration:7. Pour the solution in beaker #6 into beaker #1. Swirl the solutions and it should be a yellow- like color, call it lemonade.8. Pour the solution from beaker #1 into beaker #2. The solution formed should be an orange-red color, call it iced-tea.9. Pour the solution from beaker #2 into beaker #3. The solution formed should be dark red, call it red wine.10. Pour the solution from beaker #3 into beaker #4. The solution formed should be blue-black like grape juice.11. Pour the solution from beaker #4 into beaker #5. The solution formed should be yellow, we're now back to lemonade.**Leave a small amount of solution behind each glass to display the color changes. Explanation: The element iron is the dominant element throughout the experiment and is present as the 3+ ion. Each beaker is filled with a different chemical solution which will react with the iron ions to form a new compound with a different color. The idea of switching partners is present when each reaction takes place. The first reaction between iron and water simply dilutes the ferric chloride and makes the normally orange solution into a dilute yellow.The second reaction shows what happens when a low concentration of ammonium thiocyanate and ferric chloride will create iron thiocyanate complex. The third beaker illustrates the reaction between a higher concentration of ammonium thiocyanate and the iron ions present from the second beaker. The fourth beaker demonstrates the reaction between tannic acid and iron ions. The result is the compound iron (III) tannate. At the end, the yellow solution is created when the compound iron (III) oxalate is formed. In each of the above two reactions, the first iron compound is destroyed and changed into a new more stable compound. In each case the compounds switch partners.One reaction is used to show the switch partners concept:Beaker #3: FeCl3 + 3 KSCN ---> Fe(SCN)3 + 3 KCl.Safety: Use normal precautions when handling the chemicals.Disposal: The final products may be poured down the drain.

Lemon Shell GameScience Concept:How a lemon reacts with acids and bases.Materials: water 0.1 M sodium hydroxide (NaOH) phenolphthalein 3 lemons knife syringe with no tip or plastic tip 50 mL beakerDirections:1. Pour 5 mL of the 0.1 M sodium hydroxide/water solution into 50 mL beaker.2. Add four drops of phenolphthalein into beaker.3. Use the syringe to suck up 2-3 ml the pink basic solution from the beaker.4. In just one of the lemons make a tiny hole for the syringe to go through.5. Inject the pink basic solution into the lemon.6. Mix lemons around, and have kids try to guess which is the pink lemon.7. Then cut open the lemons to find the pink one.8. After, squirt some pink NaOH on open lemon to show how pink disappears.Explanation:When the sodium hydroxide, which is a base, is mixed with phenolphthalein, it turns pink. When the base is neutralized by the acid, citric acid, which is present in lemons, the pink solution turns colorless. This happens because the base is neutralized in an acid solution, which causes the indicator to become colorless. All of the base is neutralized by the citric acid. The inside of the lemon stays acid so the phenolphthalein indicator is colorless.NaOH + phenolphthalein ----> pink colored solutionneutralization: 3 NaOH + H3-citric acid -----> 3 HOH + Na3(citrate)Disposal:The lemons can be disposed of in the garbage, and the remaining solution can be disposed of in the sink

Solid WaterScience Concept:A polymer absorbs a large amount of water by the process called osmosis.Materials:2- 400 mL beakersTable saltSodium polyacrylate WaterFood coloringStirring rodDirections:1. Measure 300 mL of water in one of the 400 mL beakers.2. Add a few drops of food coloring to the water.3. Measure out 5 -7 grams of the sodium polyacrylate and pour into the other 400 mL beaker.4. Pour the water quickly into the beaker containing the sodium polyacrylate from a height of about 12 inches with a lot of vigorous splashing. This is to ensure good mixing as stirring after the addition of the water does not work properly. Pour back and forth quickly and it will quickly thicken into a solid.5. Turn the beaker upside down to demonstrate how it has become solid.6. Measure out about 10 grams of table salt.7. Pour the salt onto the solid water gel and stir until the mixture becomes a liquid again.8. Pour the liquid back into the first beaker again to demonstrate that it is a liquid again.Explanation:The white powder is a polymer of sodium polyacrylate. The particles have a membrane of the polyacrylate which surrounds the sodium ions. By the process of osmosis, the water is attracted to the sodium polyacrylate because it contains sodium ions (an ion that you would find in table salt). It expands the crystals of the powder and makes it into solid like gel. This is an example of an osmosis process reaction involving a polymer. Sodium polyacrylate contains a high number of sodium ions within each particle. Water is highly attracted to sodium ions. So when the water is poured into the beaker containing the sodium polyacrylate, it moves into the individual powder particles and expands the polymer particles to become a solid like gel.When the table salt was added to the gel, it caused it to turn back to a liquid because salt has a higher concentration of sodium ions on the outside of the polyacrylate particles. The water was attracted to the salt and this caused the water to leave the polymer particles which then collapsed and become a liquid again. This process is called osmosis.Sodium polyacrylate is the material found in baby diapers.Safety: These chemicals are not harmful. Disposal: May be disposed of in sink or garbage.

Ghost CrystalsSodium polyacrylate can also make larger crystals that cannot be seen in water. Tie a string around a crystal and float in a beaker. Pull it out so students can see the ghost crystal. The crystals are almost all water so the light rays do not change as they travel through water and the the crystal. However, when you pull the crystal out of water, it has a different index of refraction than air and can be seen. Sometimes, these water absorbing crystals are put in dirt to help new plants survive while they grow. The crystals absorb water when it rains and slowly release it as the dirt dries out.

Vitamin C Clock ReactionConcept:A delayed chemical reaction occurs with the mixture of Iodine and starch by adding Vitamin C.Materials: 2 - 250 mL beakers Liquid laundry starch Distilled water 100 mL graduated cylinder 500 mg Vitamin C tablet (C6H8O6) 25 mL graduated cylinder Tincture of iodine - (2%) (I2) Hydrogen peroxide - (3%) (H2O2) Light Box Pre-Demo Preparation:Vitamin C stock: Crush Vitamin C tablet in 30 mL distilled water. Break up so no pieces of solid can be seen. (Solution will be slightly hazy.)Solution A: 1. Place 60 mL distilled water in beaker A.2. Add 3.5 mL Vitamin C stock.Solution B: 1. Place 60 mL distilled water in beaker B.2. Add 15 mL hydrogen peroxide.3. Add 2 mL laundry starch.Directions: Place beakers on light box.1. Add 5 mL tincture of iodine to solution A and stir. This solution is now colorless2. Add solution B to solution A.3. Stir a few times and wait. It should take approximately 1 - 2 minutes for the solution to suddenly turn blue-black.Introduction: Clocks have been around to measure time thousands of years. They have been made from different materials, like stone on a sundial, and liquid crystals in watches. A clock can be formed from molecules that react at a rate from the time the chemicals are mixed to the time the reaction occurs.Explanation: There are two forms of iodine:Element form (Iodine): I2 + starch -------> blue Ion form (Iodide): I- + starch --------> colorless There are two reactions taking place simultaneously in the solution:#1. 2I- + H2O2 ---(slow)-------> I2 + H2O#2. I2 + Vitamin C ----(fast)----> I (colorless)In Reaction # 1 iodide ions react with hydrogen peroxide to produce iodine element which is blue in the presence of starch. BUT, BUT......In Reaction # 2 The Vitamin C is immediately reacting with any iodine formed in reaction # 1. The net result, at least for part of the time is that the solution remains colorless with excess of iodide ions being present.Now after a short time as the reactions keep proceeding in this fashion, the Vitamin C gets gradually used up. The Vitamin C creates a clock reaction (1 - 2 minutes) and once it is used up, the solution turns blue, because now the iodine element and starch are present.Safety Precautions: Be careful when working with the iodine - it stains.Waste Disposal: Dispose all liquids down the drain with plenty of water.

LuminolConcept: Two mixed liquids emit a blue chemiluminescent glow.Materials: 4.0 g anhydrous sodium carbonate (Na2CO3) 0.2g luminal (3-aminophthalhydrazide)\ 24.0 g sodium bicarbonate (NaHCO3) 0.5 g ammonium carbonate monohydrate 0.4 g copper (II) sulfate pentahydrate (CuSO4*5H2O) 50 ml 3% hydrogen peroxide (H2O2) Distilled water Glass funnel, ring stand, ring and 6-8 clamps, 2 m transparent tygon tubing, 1 L Erlenmeyer flask, 2- 100 ml beakers, 2 1-L beakers of flasks.Pre-demo preparation:1. Prepare solution A. In a 1 L flask dissolve 4.0 g sodium carbonate in 500 ml distilled water. Add 0.2 g luminal and stir to dissolve (this step may take awhile). Add 24.0 g sodium bicarbonate, 0.5 g ammonium carbonate monohydrate, 0.4 g copper (II) sulfate pentahydrate and stir until all the sold is dissolve. Dilute to a final volume of 1 L with distilled water. 2. Prepare solution B. In the other 1 L flask dilute 50 ml of 3% hydrogen peroxide to 1 L with distilled water.3. Prepare a coil to send the glowing luminal through. Set up the ring stand with the funnel and ring as close as possible to the top. Place 6-8 clamps along the remainder of the ring stand. Connect the tygon tubing to the glass funnel and coil it around the ring stand and through the clamps to form a spiral. Place the 1 L Erlenmeyer flask in the receiving end of the tubing.*** If the presentation room cannot be made completely dark, try using a black cardboard background. Other creative ways of the arranging the tubing for presentation can be explored.Directions: 1. Measure out 100 ml solution A and B in separate beakers.2. Turn out the lights. Check that the receiving Erlenmeyer flask is at the end of the tubing. Simultaneously pour solutions A and B into the funnel. The solution with travel through the spiral of tubing and glow for approximately 2 minutes.Safety Precautions:Waste Disposal: Rinse the tubing with distilled water when finished. The materials can be placed down the drain.

Alka-Seltzer and Gas SolubilityConcept: Solubility of gases decreases as temperature increases.Materials: Alka-seltzer tablets Bromothymol blue indicator, (0.04%, 10 ml) 1 M sodium hydroxide (5 ml) Ice bath 3-250ml beakers 2 thin stem beral pipets Hot plate Stirring rod 3 large test tubes & rack ThermometerDirections:1. Add 200ml tap water to each beaker. Place A in an ice bath, B at room temp, and C on a hot plate. Heat C to 75-80C, then place all three on benchtop. 2. Add 3 ml bromothymol blue to each beaker (should be blue-green).3. Drop a alka-seltzer tablet in the beaker A and C. (hot water reaction is quick, cold water takes several minutes). Note the changes taking place final color change.4. Measure the temperature of each beaker. Label the test tubes with the temperature and add 25 ml of each sample.5. Add 1 M NaOH dropwise into the cold water until it matches B. Count the number of drops with students.6. Repeat step 5 with C.Explanation: Alka-seltzer contains aspirin, sodium bicarbonate, and citric acid. Sodium bicarbonate is a weak base and citric acid is a weak acid, so these buffer the solution. The solubiliby of carbon dioxide decreases as temperature increases. Safety Precautions: wear goggles when working with sodium hydroxide.Waste Disposal: Can be disposed down drain.

Thionin: The Two-Faced SolutionConcept: Light and chemical energy can make a solution that is two colorsMaterials: Iron(II)sulfate (2.0g) 1M sulfuric acid (100ml) .001 M thionin solution (10ml) Distilled water (500ml) Large beaker or fish bowl Overhead projector Aluminum foil/black construction paperSolution Preparation:1. Prepare .001 M thionin solution by dissolving 0.023 g thionin in 100 ml distilled water. Solution must be used within one week.Demonstration Preparation:2. Mix 10 ml 0.001M thionin solution, 100ml 1M sulfuric acid and distilled water to make a solution with a final volume of 600ml.3. In a dark room, add 2.0g iron(II)sulfate. Stir to dissolve. Pour into fishbowl.4. Cover half of an overhead projector with tinfoil and construction paper.Directions:1. Place the fishbowl on the overhead projector so half is over the darkened area. Turn on the projector. (Half the solution will quickly turn to colorless with a distinct vertical line).2. Lights can be turned off and this can be repeated several times.Explanation: The oxidized form of thionin is purple, while the reduced form is colorless.Safety Precautions: Be cautious of sulfuric acid. Wear gloves and apron.Waste Disposal: The solution can be disposed of down the drain when complete.

Milk of MagnesiaConcept: Milk of Magnesia is an antacid to work with stomach acid. Universal indicator is used to show it working.Materials: Milk of magnesia (20ml) 3M HCl (20ml) Universal indicator (4-5ml) 1 L beaker Magnetic stir plate and stir bar Crushed ice and water (780ml)Demonstration Preparation:1. Measure 20 ml milk of magnesia and 780 ml water in a 1 L beaker. Place on stir plate with stir bar and to create a vortex.2. Add 4-5 ml universal indicator solution.Demonstration Directions:3. Add 2-3 ml 3M HCl.4. Repeat until the solution turns to blue-purple.Explanation: Milk of Magnesia contains Mg(OH)2 which is in suspension in the solution. In cold water, magnesium hydroxide has a low solubility resulting in a basic solution with a pH of about 10. Hydrochloric acid is added to simulate stomach acid which neutralizes the magnesium hydroxide and has excess acid making an acidic solution. The excess acid sin solution causes more suspended magnesium hydroxide to dissolve, slowly neutralizing the acid and creating a basic solution. As this occurs, the universal indicator displays all the color changes.Safety Precautions: Wear goggles and lab apron. Waste Disposal: Neutralize solutions and dispose down drain.

Glycerin Soap Bubbles/Kid in a BubbleConcept: Prepare high-quality bubbles to make large bubbles around a student.Materials: Dish soap (Dawn or Joy) Glycerin Distilled water 1 L beaker Large plastic swimming pool. Bubble wand from hula hoop and PVC pipe handle.Directions:1. Mix 100ml dish soap with 50 ml glycerin.2. Add to 850 ml distilled water. Stir solution.3. Pour solution in a ~4 ft plastic swimming pool.4. Have a student stand on a stool in the swimming pool.5. Use a hula hoop to make a large bubble around the student.

Hydrogen BubblesConcept: Create soap bubbles filled with H2 gas which can be ignited in your hand.Materials: Glycerin soap bubble mixture 1M H2SO4 1 teaspoon Mg(s) 500 ml erlenmeyer flask with spindle tube and two-holed stopper 1L Plastic pop bottle with nose cut off Ring stand and clamp Bucket of water.Directions:1. Set up the Erlenmeyer flask with stopper. Put spindle tube in one hole of the stopper and tubing connecting to the pop bottle in the other. Add 1 teaspoon solid Mg to the flask.2. Cut the top 4-inches off a 1 L plastic pop bottle. Place a stopper in the neck of the pop bottle and connect the tubing. Use a clamp to hold the pop bottle upside-down on the ring stand. Put soap bubble mixture in the pop bottle.3. Add H2SO4 to the Erlenmeyer flask through the spindle tube. (Volume depends on the amount of soap bubbles you wish to create).4. Dip your hand in a bucket of water and then in the pop bottle to scoop out H2 bubbles.5. Have another person to hold a flaming splint with tongs to ignite the bubbles.Explanation: Soap bubbles are a film consisting of two layers of soap molecules around a thin layer of water molecules. This film forms a spherical shape (the shape with a minimum surface area) around air. The film forms because one end of the soap molecule is hydrophilic (water-loving) and the other end is hydrophobic, and avoids water and positions itself away from the water. Bubbles pop when the water evaporates. Glycerin forms weak hydrogen bonds with the water molecules, which slows evaporation and helps to extend the life of bubbles. Safety Precautions: Remove jewelry from hands before igniting H2 bubbles.Waste Disposal: Soap bubble solution is safe to dispose.

Rainbow ReactionConcept: A rainbow of colors appears in a large graduated cylinder as density separates solutions with different pH.Materials: 0.1 M HCL Saturated Na2CO3 solution Universal indicator Large graduated cylinder (1 L) Beral-type pipetsDirections: 1. Add 90 ml universal indicator to large cyulinder. Add 500 ml HCL solution. Swirl to mix.2. Fill pipet with sodium carbonate solution. Tilt the cylinder and slowly add sodium carbonate down the sides of the cylinder. This solution will sink to the bottom of the graduated cylinder. Continue adding sodium carbonate in this manner and a rainbow spectrum of colors will appear.Explanation: HCl is an acidic solution. As sodium carbonate is added it sinks to the bottom due to density. Carbonate ions then drift upwards and neutralize the hydrochloric acid. The changes in pH are displayed as different colors by the presence of universal indicator.Safety Precautions: Use caution with acid and base solutions. Wear goggles and apron.Waste Disposal: Neutralized solution may be dispose of in the sink.

NitrocelluloseConcept: Nitrocellulose forms nitrogen gas with the heat generated by touching with a glass rod.Materials: Cotton balls Concentrated nitric acid (HNO3) Concentrated sulfuric acid (H2SO4) Ice bath 250 ml beaker and watch glass Stirring rod and Bunsen burnerNitrocellulose Preparation:1. Place 12 cotton balls in beaker.2. Combine 50 ml concentrated nitric acid with 100 ml concentrated sulfuric acid and pour onto cotton balls.3. Cover the beaker with a watch glass and place in ice bath in a fume hood and let sit overnight.4. Rinse the material several times with water and allow to dry.5. Store in plastic bags.Demonstration Directions:1. Place a small ball of nitrocellulose on the lab bench or on iron base of a ring stand.2. Heat a glass stirring rod with a Bunsen burner.3. From a distance, touch the hot end of the stirring rod to the nitrocellulose, which will immediately ignite and burn with a flash.Explanation: The heat from the stirring rod is sufficient energy for the trinitrocellulose to react and form nitrogen gas.Safety Precautions: Use extreme caution when handling concentrated acids. Wear acid gloves, goggle, and apron and work under a hood. Only an instructor should handle concentrated acids.Waste Disposal: There should not be any waste.

Burning Water/Burning MoneyConcept: Ethanol looks like water, but has a different flammability.Materials: Water Lighter fluid 50% ethanol solution 1 L Erlenmeyer flask 500 ml beaker Dollar bill Matches and tongsBurning Water Directions:1. Add 2-3 ml lighter fluid to the Erlenmeyer flask without audience seeing.2. Add water to the new, clean flask to fill to the neck. 3. After about 30 sec, ignite the surface water, holding a lighted match with tongs.Explanation: Lighter fluid is less dense than water and will float to the top of the surface. It will then ignite with a match and burn.Burning Money Directions:1. Fill the beaker with 50% ethanol by volume solution.2. Using tongs to hold a dollar bill, dip the money in the solution. Use tongs to hold a lighted match and hold near the bottom of the dollar bill.Explanation: The ethanol will burn off the dollar bill and the water will evaporate before the paper will ignite.Safety Precautions: Use caution when handling matches.Waste Disposal: Ethanol solution can be stored and reused.

Flaming Salts

Concept: Salts produce different colored flames.Materials: 7 evaporating dishes Methanol Tongs and matches NaCl, BaCl2, CuCl2, LiCl2, SrCl2, KCl, FeCl2Demonstration Preparation:1. Place teaspoon of a salt into each evaporating dish.2. Add 3-5 ml methanol to each dish.Demonstration Directions:3. Using tongs to hold a lighted match, light each dish.4. Turn out the lights. Burning will stop when the methanol is consumed.Explanation: Salts emit visible light when they absorb energy from a flame. The light is emitted when electrons that have been elevated to higher energy levels by burning methanol return to lower energy levels. The energy associated with the drop in energy of electrons is different for each salt, resulting in different colors of light emitted.Waste Disposal: Dishes can be reused for multiple demos. Dissolved salts left unburned can be washed down the drain.Safety: Have a teacher pour the methanol and supervise burning and check that evaporating dishes are a safe distance from anything flammable. Use caution lighting the methanol.