Chemistry/Chem AP Demos

PHOTOCHEMICAL BLEACHING OF  METHYLENE  BLUE:  A  ZEROTH  ORDER REACTION
TOPIC: Reaction Kinetics

REFERENCE A Demo A Day, p. 234

EQUIPMENT
 * Light box or overhead projector
 * 2 – 100 mL beakers

CHEMICALS
 * 1.0 g of iron(II) sulphate, FeSO4
 * 50 mL of 0.1 M sulphuric acid
 * dropper bottle containing 1% methylene blue

PROCEDURE

What is Happening: The reaction is shown below.

Fe2+ + oxidized methylene blue (blue) + hv <===> Fe3+ + reduced methylene blue (colourless)


 * The rate of the reaction is controlled only by the amount of light and is independent of reactant concentrations. Hence, the reaction is ZEROTH ORDER with respect to reactant concentrations.

THE CHAIN REACTION  BETWEEN  HYDROGEN  AND  CHLORINE
TOPIC: Reaction Kinetics

REFERENCE Chem 13 News, November 1976, p. 7 (modified by Jim Hebden)

EQUIPMENT
 * thin plastic bag, 1-2 L capacity maximum, with twist-tie
 * 5 x cm piece of aluminum foil
 * Tesla coil
 * 30-40 cm length of rubber tubing
 * tubing clamp

CHEMICALS
 * small lecture bottle of hydrogen gas
 * small lecture bottle of chlorine gas

PROCEDURE

ANTI–BUBBLES
TOPIC: Gas Laws

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 86

EQUIPMENT
 * 1 L beaker
 * 50 mL beaker (this is critical)
 * 10 mL graduated cylinder

CHEMICALS
 * 30–40 mL of clear dish washing detergent
 * sodium chloride (alternate variation)
 * food colouring (alternate variation)

PROCEDURE

DISCREPANT BALLOONS
TOPIC: Gas Laws

REFERENCE Twenty Demonstrations Guaranteed to Knock Your Socks Off! Volume II, p. 35

EQUIPMENT
 * 2 balloons
 * 2 – #4 or #5 one–hole stoppers
 * 2 pieces of 5 cm long glass tubing to fit the one–hole stoppers
 * rubber tubing, 10 cm
 * pinch clamp for rubber tubing

PROCEDURE

CRUSH THE CAN
TOPIC: Gas Laws

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p.

EQUIPMENT
 * aluminum soda can
 * hot plate
 * shallow pan or dish
 * beaker tongs or Hot Hand

PROCEDURE

HERO’S FOUNTAIN
TOPIC: Gas Laws

REFERENCE Twenty Demonstrations Guaranteed to Knock Your Socks Off! Volume II, p. 27

EQUIPMENT
 * 3 – 2 L soda bottles
 * 3 – 2 hole #3 stoppers
 * 100 cm of glass tubing to fit stoppers, cut as follows:
 * 40 cm length, 32 cm length, 10 cm length and three 6 cm lengths


 * 3–4 m of rubber tubing to fit glass tubing (cut into 2 pieces, each about 1.5–2 m long)
 * plastic pipet, cut to give a nozzle (as shown in the diagram below)

PROCEDURE

MULTI–COLOURED AMMONIA FOUNTAIN
TOPIC: Gas Laws

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 150

EQUIPMENT
 * 3 – 1 L round bottom flasks
 * 3 – two–hole stoppers to fit flasks
 * separatory funnel
 * one–hole stopper to fit separatory funnel
 * 2 L beaker
 * 3 – regular stands
 * 1 – tall stand
 * 4 – utility clamps
 * 1 – long piece of glass tubing (see reference)
 * 3 – U-shaped pieces of glass tubing (see reference)

CHEMICALS
 * source of ammonia gas (lecture bottle)
 * 10 mL of universal indicator
 * 100 mL of 6 M acetic acid

PROCEDURE

THOUGHT EXPERIMENT : LIFE  ON  “PLANET  V”
TOPIC: Gas Laws

REFERENCE Twenty Demonstrations Guaranteed To Knock Your Socks Off II, p. 30

EQUIPMENT
 * Handout sheet (following)

PROCEDURE

THOUGHT EXPERIMENT : LIFE  ON  “PLANET  V”
(Adapted from Twenty Demonstrations to Knock Your Socks Off, Volume II)

Imagine you have been relocated to Planet V, a planet just like Earth, but with no atmosphere at all. Which of the items listed below would still work on this planet and which ones would not? For those things that would work, would they work exactly the same? For those things that would not work, can you think of modifications that could enable them to work?

THE EFFECT OF  PRESSURE  ON  BOILING  POINT
TOPIC: Gas Laws

REFERENCE Chemical Demonstrations: A Sourcebook for Teachers, Volume 1, p. 21

EQUIPMENT
 * 250 mL beaker
 * 50–60 mL syringe with Luer lock
 * stand with ring and ceramic pad
 * bunsen burner and flint striker
 * thermometer

CHEMICALS
 * distilled water

PROCEDURE

BOILING AT REDUCED  PRESSURE :  BOIL  IT  COLD
TOPIC: Gas Laws

REFERENCE A Demo A Day – A Year of Physical Science Demonstrations, p. 70

EQUIPMENT
 * 250 mL side arm vacuum filtration flask
 * 2–hole rubber stopper to fit flask
 * thermometer
 * 15 cm of glass tubing to fit 2–hole stopper
 * 5 cm of latex tubing to fit glass tubing
 * pinch clamp
 * ring and stand
 * utility clamp
 * vacuum tubing
 * aspirator pump (NOT vacuum pump)
 * boiling chips

CHEMICALS
 * 100 mL of acetone

PROCEDURE

BOILING WATER AT  LESS  THAN  100oC
TOPIC: Gas Laws

REFERENCE Chem 13 News, November 1976, p. 8

EQUIPMENT
 * 500 mL or 1 L thick–walled round bottom flask, free of scratches or hairline cracks
 * rubber stopper to fit flask (Note: the stopper will be partially sucked into the flask by a vacuum developing inside the flask, so make sure the stopper is not too small)
 * towel or Hot Hand™
 * stand and ring, with wire gauze pad
 * clamp for stand
 * bunsen burner and flint striker

CHEMICALS 150–200 mL of distilled water

PROCEDURE What is happening: Water boils when its vapour pressure equals the pressure of the atmosphere pressing down on the water’s surface. When the flask is boiling, all the air is pushed out and the only gas remaining inside is water vapour. When the flask cools, the pressure inside remains more or less equal to the vapour pressure of the water. The stream of cold water on the upper side of the flask condenses the vapour and lowers the vapour pressure to a value lower than that created by the still–hotter liquid below, giving rise to a dramatic “bumping” as the liquid suddenly boils.

HOW ICE SKATES  WORK
TOPIC: Phase Diagrams

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 84

EQUIPMENT
 * cylinder of ice, 30 x 5 cm
 * 2 – ring stands
 * 2 – rubber insulated clamps
 * 50 cm of strong thin wire (such as piano or guitar wire)
 * 2 – 1 kg masses

PROCEDURE

TRIPLE POINT OF  WATER
TOPIC: Phase Diagrams

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 128

EQUIPMENT
 * 500 mL filter flask
 * one–hole stopper to fit flask
 * thermometer
 * 25 x 100 mm test tube
 * vacuum pump
 * rubber vacuum tubing
 * safety shield

CHEMICALS
 * a few chips of ice
 * 5 mL of distilled water

PROCEDURE

EQUILIBRIUM AND ELASTIC  BANDS
TOPIC: Thermodynamics

REFERENCE commonly known

EQUIPMENT
 * Large, thick elastic band
 * stand with ring
 * large weight (500 g or so)
 * pieces of wire to secure rubber band to ring and weight to rubber band
 * bunsen burner and flint striker
 * electronic balance

PROCEDURE

SUPERHEATED STEAM
TOPIC: Thermodynamics

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 118

EQUIPMENT
 * 40–50 cm of 3/8 OD copper tubing
 * 250 mL erlenmeyer flask
 * one–hole stopper to fit flask (hole size to fit tubing)
 * ring stand
 * 2 – rubber coated utility clamps
 * Meker burner and flint striker
 * hot plate
 * sheet of paper
 * tongs to hold paper sheet

PROCEDURE

MOLARITY VS MOLALITY
TOPIC: Colligative Properties

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 194

EQUIPMENT
 * 2 – 1 L graduated cylinders
 * 12 large rubber stoppers

PROCEDURE

ACID–WATER PUZZLE
TOPIC: Colligative Properties

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 141

EQUIPMENT
 * 2 – 250 mL beakers
 * 2 – thermometers
 * 2 – 100 mL graduated cylinders

CHEMICALS
 * 200 mL of 9 M sulphuric acid (slowly add 100 mL of concentrated sulphuric acid to 100 g of ice
 * — care it gets VERY HOT! Do this in advance so that the acid is at room temperature.)


 * 100 g of ice
 * 100 mL of ice water

PROCEDURE

GROWTH OF CHEMICAL  “CELLS”  BY  OSMOSIS
TOPIC: Colligative Properties

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 195

EQUIPMENT
 * Light box
 * 250 mL beaker
 * 100 mL graduated cylinder

CHEMICALS
 * 100 mL of 3% potassium ferrocyanide (3.0 g K4[Fe(CN)6]•3H2O dissolved in 97 mL of distilled water)
 * 6–8 small crystals of copper(II) sulphate (slightly larger than a pinhead)

PROCEDURE

LEWIS ACID–BASE REACTION
TOPIC: Acids and Bases

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 202

EQUIPMENT
 * 2 – 18 x 150 mL test tubes
 * 1 oz wide mouth bottle with rubber stopper to fit
 * 600 or 1000 mL beaker (heavy duty)
 * 4–6 inch paddle type balloon (heavy duty)
 * tape or rubber band to secure cut–off balloon around top of beaker
 * gas bubbler tube

CHEMICALS
 * 20–30 g of FRESH 4 mesh calcium oxide
 * source of carbon dioxide
 * dropper bottle of universal indicator

PROCEDURE

AMPHOTERIC PROPERTIES OF  METAL  HYDROXIDES
TOPIC: Acids and Bases

REFERENCE Chemical Demonstrations: A Sourcebook for Teachers, Volume 2, p. 171

EQUIPMENT
 * 1 L beaker
 * 2 – 400 mL beakers
 * stirring rod

CHEMICALS
 * 100 mL of 0.5 M zinc chloride (dilute 6.8 g of ZnCl2 to 100 mL)
 * 250 mL of 1.0 M sodium hydroxide (dilute 10.0 g of NaOH to 250 mL)
 * 250 mL of 1.0 M hydrochloric acid (dilute 20.7 mL of concentrated HCl to 250 mL)

PROCEDURE

OPTICAL ROTATION OF  SUGARS
TOPIC: Electronic Structure of Atoms

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 122

EQUIPMENT
 * Overhead projector
 * 250 mL beaker
 * 2 pieces of polaroid film
 * protractor

CHEMICALS
 * white Karo™ syrup

PROCEDURE

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POLYMER CRYSTALLINITY
TOPIC: Electronic Structure of Atoms

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 276

EQUIPMENT
 * Two pieces of polarizing film
 * Overhead projector
 * Scotch tape
 * samples of different types of plastics: plastic film, “six pack” ring, polyethylene pipet, etc.

PROCEDURE

ELECTROMAGNETIC RADIATION ON  THE  OVERHEAD
TOPIC: Electronic Structure of Atoms

REFERENCE Chemistry Demonstration Aids That You Can Build, p. 9

EQUIPMENT
 * See reference and sheets following

PROCEDURE





PARAMAGNETIC COMPOUNDS : SWINGING  ELECTRONS
TOPIC: 	Electronic Structure of Atoms

REFERENCE A Demo A Day: A Year of Chemical Demonstrations, p. 124

EQUIPMENT
 * very strong magnet
 * 8 – 18 x 150 mm test tubes
 * 2 – ring stands with clamps
 * horizontal bar (extra rod from ring stand)
 * thread

CHEMICALS
 * calcium sulphate, CaSO4 (any hydrate)
 * manganese(II) sulphate, MnSO4 (any hydrate)
 * copper(II) sulphate, CuSO4•5H2O
 * zinc sulphate, ZnSO4 (any hydrate)
 * 100 mL of saturated calcium sulphate
 * 100 mL of saturated manganese(II) sulphate
 * 100 mL of saturated copper(II) sulphate
 * 100 mL of saturated zinc sulphate

PROCEDURE

QUANTIZED PHOSPHORESCENCE
TOPIC: Electronic Structure of Atoms

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 65

EQUIPMENT
 * 100 mL graduated cylinder
 * one sheet of each of red, blue and green cellophane, in cardboard frames
 * scotch tape
 * flashlight

CHEMICALS
 * 10 g of sodium fluorescein dissolved and diluted to 100 mL

PROCEDURE

POLAROID
TOPIC: Electronic Structure of Atoms

REFERENCE
 * commonly known

EQUIPMENT
 * 4 pieces of polaroid film, preferably as large as possible

PROCEDURE

What is Happening: The polaroid plastic can be thought of as a picket fence. A skip rope can be waved up and down and the wave will pass through the pickets. If the wave were to go side to side, the sideways wave would be stopped at the up and down pickets.

Aligning the polaroid pieces parallel to each other, allowing light to pass through, is equivalent to having two fences one behind each other. A wave that passes through one fence can pass through the next one. If the two fences are aligned so that the pickets are up-down on one and sideways on the next, no wave can get through. Similarly, when the polaroid is aligned 90o to each other, no light passes through.

Strictly speaking, the light passing through the first piece of polaroid is said to become “plane polarized” and now vibrates up and down, say, only. If the light passing through one piece of polaroid is passed through a second piece of polaroid, the amount of light passing through the second piece is proportional to the cosine of the angle between them. For example, when the pieces are parallel (0o angle between them), 100% of the light gets through; when the pieces are at 90o, 0% of the light gets through.

If you have two pieces at 90o to each other, inserting a third piece of polaroid at 45o to the other two causes an interesting effect. When light is plane polarized by passing through the first sheet, about 71% of the light passes through a second polaroid at 45o to the first sheet. But the light passing through the second sheet is now plane polarized by the second sheet, 45o to the first sheet. Passing the light from the second sheet through a third sheet 45o to the second (and 90o to the first) again allows 71% of the light from the second sheet to pass through the third. Hence, where previously 0% of the light passed through two pieces at 90o to each other, the presence of the third sheet at 45o allows 50% (71% of 71%) to pass through now.

CRYSTAL COLOUR CENTRES :  COLOURFUL   ELECTRONS
TOPIC: Electronic Structure of Atoms

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 152

EQUIPMENT
 * 2 – heavy walled ignition tubes
 * ring stand and clamp
 * one hole stopper to fit ignition tube
 * 5 cm length of glass tubing to fit stopper
 * vacuum pump
 * rubber vacuum tubing to connect to 5 cm glass tube
 * tesla coil
 * 250 mL beaker
 * stirring rod

CHEMICALS
 * 2 g of potassium chloride crystals, KCl

PROCEDURE

THERMCELLS ARE SIMPLE  BATTERIES  (THE  BECQUEREL  EFFECT)
TOPIC: 	Electrochemistry:

REFERENCE A Demo A Day, Volume 2: Another Year of Chemical Demonstrations, p. 264

EQUIPMENT
 * 10 mm OD glass tubing, 1 m long
 * 2 – rubber stoppers to fit glass tubing
 * 2 – 50 cm pieces of bare copper wire
 * voltmeter with alligator leads
 * large ring stand and 2 clamps
 * heat gun or blow dryer
 * small drill (1/16” or smaller) or dissecting needle

CHEMICALS
 * 150 mL of 0.0050 M copper (II) sulphate, CuSO4

PROCEDURE

COLOUR EFFECTS DUE  TO  LIGAND  EXCHANGE  IN  NICKEL  COMPLEXES
TOPIC: VB and MO Theory

REFERENCE Chemical Curiosities: Spectacular Experiments and Inspired Quotes, p. 105

EQUIPMENT
 * 6 – 18 x 150 mm test tubes
 * dropping pipet

CHEMICALS
 * nickel(II) chloride, NiCl2•6H2O
 * concentrated ammonia
 * 10 mL of ethanol

PROCEDURE

COLOUR EFFECTS IN  AQUEOUS  SYSTEMS  CONTAINING  DIVALENT  METAL  IONS DERIVED  FROM SELECTED 3d  ELEMENTS
TOPIC: VB and MO Theory

REFERENCE Chemical Curiosities: Spectacular Experiments and Inspired Quotes, p. 114

EQUIPMENT
 * 8 – 18 X 150 mm test tubes
 * test tube rack
 * 25 mL graduated cylinder
 * 10 mL graduated cylinder

CHEMICALS
 * 1.5 g of solid manganese(II) sulphate
 * 1.5 g of solid iron(II) sulphate
 * 1.5 g of solid cobalt(II) sulphate
 * 1.5 g of solid nickel(II) sulphate
 * 1.5 g of solid copper(II) sulphate
 * 1.5 g of solid zinc sulphate
 * 1.5 g of solid ammonium metavanadate
 * 1.8 g of solid chromium(III) sulphate
 * a scoopful of zinc granules
 * 10 mL of concentrated sulphuric acid
 * 50 mL of 20% sulphuric acid (CARE: slowly add 10 mL of concentrated H2SO4 to 40 mL of cold water)
 * 20 mL of n–hexane

PROCEDURE

PARAMAGNETIC OXYGEN GAS
TOPIC: VB and MO Theory

REFERENCE Journal of Chemical Education, Vol. 67, p. 63 (1990)

EQUIPMENT
 * small Petri plate
 * very strong magnet (example: neodymium)
 * rubber tubing (to lead from oxygen source to demonstration)
 * pipette to fit tubing, with thin end

CHEMICALS
 * Source of oxygen
 * Soap bubble solution

PROCEDURE