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.