A:  Gas laws

 

 

1.      Air Thermometers( Charles’s law)

 

Heating of cooling a glass bulb results in changes in the relative heights of two columns of colored liquid. ( Can also use this to demonstrate exothermic and endothermic solution reactions.)

 

Air Thermometers is on Desk G

 

2.      Collapse of Balloon in Liquid N2

 

When liquid N2 is poured over a balloon, the balloon shrinks. If filled with helium, the balloon can also be used to lift a small aluminum weight.

 

Balloons in Drawer G2

Dewars in Cabinet A

Weight and string in Drawer A1

 

3.      Molecular Motion Demonstrator (for overhead demonstration of all gas laws).

 

The behavior of gas molecules as described by the kinetic molecular theory of gases is simulated with small, hard balls and a vibrating stage.

 

Molecular Motion Demonstrator on Shelf B1

 

4.      Collapsing Can

 

Water is boiled in a can until the air inside is replaced by steam. The can is then sealed, and is dramatically crushed as it cools to room temperature. ( Note: See Fisher catalog to order more.)

 

Cans in Drawer B3

Cans to be gathered in Recycling Bins.

 

5.      22.4 L Cube

 

Shows volumes of 1 mole of gas at standard temperature and pressure.

 

Shelf B1

 

6.      Flow of Gases Through a Porous Cup

 

Samples of various gases ( He or CO2) are allowed to flow through a porous cup. The relative rates of flow cause liquid to be forced from a flask or air to be drawn into it.

 

A porous cup on Shelf B1

He is in p-Chem lab

CO2 is in p-Chem lab

 

7.      Relative Rates of diffusion of Br2 Vapor through Vacuum and Air

 

Bromine vapor is allowed to fill two containers, one containing air and the other evacuated. The bromine fills the first container only gradually, illustrating the effect of molecular collisions on the rate of gas diffusion. The same effect is shown by the reverse process of condensing Br2 vapor to the liquid (by the use of dry ice or liquid nitrogen baths).

 

Shelf C2

Dewar for liquid N2  in Cabinet A

 

8.      Moles-Volume Correspondence in the electrolytic Decomposition of Water

 

Water is electrolyzed to hydrogen and oxygen in a 2:1 volume ratio. The identities of each inverted test tube, and igniting the hydrogen to produce a “dark”, or reigniting a glowing splint in the oxygen. Bromothymol blue or litmus in the electrolyzed solution indicates production of OH- at the H2 electrode, H+ at the O2 electrode.

 

Hoffmann apparatus is on Desk D

Power supply is on Desk B

Na2SO4 solution containing indicator is in Flammables cabinet

 

9.      Ratio of Diffusion Coefficients – Ammonium Chloride Ring

 

NH3 vapor is introduce at one end of an air-filled tube, and HCl vapor at the other. After about 20 minutes, a ting of solid NH4Cl forms inside the tube nearer to the side at which the HCl was introduced.

 

Glass tube is on sink desk.

 

10.  Effect of Gas Density on Sound Frequency – Speak after Breathing Helium

 

Helium tank is in P-chem lab.

 

11.  Gas Diffusion – H2 Whistle explosion

 

A special apparatus emits a whistle that decreases in pitch as the H2 it contains burns. Eventually, an explosion occurs.

 

A special apparatus on Window sill

 

12.  Effect of Air Pressure on Balloon size

 

After a balloon is blown up to 6” diameter, it is place in vacuum dessicator. When a vacuum is applied to the dessicator, the balloon expands dramatically.

 

Balloons are in Drawer G2

Clear tape-wrapped vacuum dessicator in on Shelf G2

Vacuum pump is Under Desk B

Vacuum hose with 3-way stocock is in Cabinet 4 tubing drawer.

 

 

 


Spectra, Chemiluminescence, Photochemistry, etc.

 

1.      spectral tubes of Gases

 

Atomic and molecular spectra can be viewed from a number of available gases: H2, O2, He, Ne, Ar, Kr, Xe, N2, O2, Hg, H2o. Co2, Cl2, Br2, I2. (Note: Power supply runs on a fresh 6 V lantern battery). These spectra can be viewed through student-held plastic diffraction gratings. A blackened box can be used to set two tubes ( e.g., H. Ne) directly above one another, using two single tube power supplies available in the physical Chemistry Lab. Close-fitting boxes should be used to cover the exit signs in Room 102.

 

All apparatus is on Desk B

 

2.      Photochemical reaction of H2 and Cl2

 

A cork-stoppered test tube is filled with a 50/50 mixture of H2 and Cl2 and clamped to a ring stand. Light from a He-Ne laser, or from a slide projector passed through a red-transmitting filter is aimed at the test tube with no result, but the beam from the slide passed through a blue filter causes an explosion and ejection of the stopper from the tube. (Illustrates activation energy, photon energy dependence on frequency, difference

between energy per photon and beam intensity).

 

Gases is in the hood.

Bubbling “J” is in Drawer G5

Test tubes and waxed corks is in Drawer C9

Optical bench with lens and filterholder is on shelf G2

Slide projector, slide projector stand/lab jack: ask front desk

Laser pointer is in Drawer C8

 

3.      Chemiluminescent Light Sticks

 

Commercially-available chemiluminescent systems produce yellowish-green or red light easily visible in a darkened room.

 

Cabinet 3

 

4.      Two-Color Chemiluminescent Clock Reaction

 

In a darkened room, a colorless liquid is poured into a solution in a large cylinder. The solution glows red ( from singlet oxygen emission) for a few seconds, then begins to foam with strong emission of blue light for several seconds. ( Note: Run 2x or 3x in 2L cylinder.)

 

Cabinet 3

 

5.      A glowing Spiral Tube

 

In a darkened room, pouring a colorless liquid and a blue liquid into a funnel with a spiral delivery tube results in blue chemiluminescence all along the tube.

 

Funnel/delivery tube apparatus on Desk A

 

6.      Fluorescence-UV lamp

 

A black light can be used to generate intense yellow fluorescence from an uranium salt or fluorescent dye.

 

Black light in Drawer C8

Uranium salts in Flammable cabinet

 

7.      Dispersion of Prism: Tungsten Source vs He-Ne Laser

 

Parallel beams from a tungsten light source and a He-Ne laser are diffracted through a prism illustration the tungsten spectrum, the monochromacity of a laser, and diffraction.

 

He-Ne laser in Drawer C8

Prism in Cabinet A1

 

8.      Diffraction of Monochromatic light through a slit( He-Ne Laser)

 

Illustrate the wave nature of light.

 

Slits in Drawer C8

 

9.      Colored Flamed with Metal Salts

 

(e.g. BaCl2, CaCl2, SrCl2, CuCl2, NaCl, LiCl, KCl). Or use spray bottle to spray solution into the flame, or a Pt wire loop to intro duce a solution drop into the flame.

 

Bunsen burner with flame attachment in Drawer B3

BaCl2, CaCl2, SrCl2, CuCl2 in cabinet under hood

 

10.  Burning of Magnesium

 

Igniting magnesium ribbon produces light and heat.

 

Mg in Flammable metals cabinet

 

11.  The Electric Pickle

 

Passing 110 V through a dill pickle produces sodium D-line emission. The emission changes of the pickle is soaked in LiCl solution.

 

Variac in Desk B

Pickle holder/electrodes assembly in Cabinet A3

 

 

 

Light Sources Available:

He-Ne Laser Pointer

He-Ne Laser

100 W Tungsten

Mercury Arc

Short Wave/Long Wave Ultraviolet

Sodium Lamp

Spectral Tubes: H2, He, Ne, Ar, Kr, Xe, N2, O2, D2, H2O, Hg, CO2, Br2, I2


Thermochemistry

 

1.      Lycopodium Dust Explosion in “Milk Can”

 

When lycopium powder is dispersed and then ignited in a metal can, an explosion blows the lid off the can.

 

Lycopodium on Shelf A1

Candles in Drawer B5

 

2.      Combustion of Magnesium in Air

 

Igniting Mg ribbon produces light and heat.

 

Mg in Flammable metals cabinet

 

3.      Thermite Reaction

 

Addition of glycerine to a pile of iron oxide, aluminum powder and KMNO4 produces flame, sparks and molten iron.

 

Flower pots in Shelf B2

Sand bucket/ring stand on floor under Desk B

 

4.      Sodium or Potassium in Water

 

A small piece of silver metal ignites and skitters around on the surface of water in a petri dish leaving behind a reddish trail. (Note: Put prtei dish in overhead projector and add ˝” depth of water with phenolphthalein indicator.)

 

Na/K in Flammable metals cabinet

 

5.      Hydrogen-Oxygen Explosion: in H2 “whistle”, in Balloons, or Soap Bubbles

 

A special apparatus emits a whistle that decreases in pitch as the H2 it contains burns, until an explosion occurs. When four balloons filled with different gas mixture are ignited, the balloons emit different intensities of sound.(Can also be done with soap bubbles.)

 

H2 whistle on Desk B

Gas “torch” in the hood

Long copper tube behind the door

 

6.      Endothermic Dissolution of Ammonium Nitrate in Water

 

When ammonium nitrate dissolves, a cooling process occurs, resulting in Change in a liquid heights in an air thermometer or freezing a beaker to a board.

 

Ammonium nitrate on shelf G2

 

7.      Exothermic Dissolution of KOH or CaCl2 in Water

 

Heat is released during the dissolution of KOH or CaCl2, producing a change in an air thermometer.

 

Air thermometer on Desk G

 

8.      Decomposition of Ammonium Dichromate

 

Ignition of a cone-shaped pile of NH4Cr2O7 crystals produces a voluminous green solid, sparks and smokes, resembling a volcanic eruption.

 

9.      Slaking of  Lime

Water added to a beaker half full of lumps of CaO (quicklime) produces steam and a temperature increase.

 

10.  Dehydration of Sugar by Sulfuric Acid

 

Concentrated H2SO4 added to granulated sugar n a 2 L cylinder produces a solid-liquid mixture that changes from white to yellow to brown to black. The mixture then expands out of cylinder accompanied by steam and the odor of burnt sugar.

 

Sugar on shelf A1

H2SO4 in acid cabinet

 

11.  Reaction of Potassium Chorate and Sugar

 

A drop of concentrate  H2SO4 added to a pile of KClO3 and granulated sugar produces smoke and purple flame. Second Method: Melt KClO3 in a heavy-walled tested tube with a Bunsen Burner. Drop in a gummi bear or small price of licorice, yielding purple flame and smoke.

 

Sugar on shelf A1

KClO3 in oxidizer cabinet

Heavy-walled test tubes on Shelf F2

Gummi bears in Drawer G2

 

12.  Combustion of Magnesium in Carbon Dioxide

 

Ignition of Mg and an Oxidizing agent in a block of dry ice result in a brilliant flare of light and a black and white residue.

Mg in Flammable metals cabinet

Plexiglas shield on Desk B

 

 

13.  Photochemical Reaction of Hydrogen and Chlorine

 

14.  Catalytic Converter

 

After the device has been heated, combustion of propane is initiated at a temperature much lower than the normal combustion temperature.

 

Catalytic converter on Desk B

Propane torch in the hood

 

15.  Rubber Band Entropy Demonstration

 

Heating a stretched rubber band (hanging a weight from a ring stand) causes it to contract, not expand. Cooling it with liquid N2 causes the rubber band to lengthen.

 

Rubber bands in Drawer G4

Weight in Drawer C6

 

16.  Shock-Induced Explosion of a KClO3 Pellet Soaked with White Phosphorus in CS2

 

A solution of white phosphorus in CS2 is placed on a pellet of KClO3. After five minutes, the pellet is detonated on a modified rat trap apparatus. (Use a bomb calorimetry pellet press  from the Phys. Chem. Lab to compress the KClO3 into a pellet.)

 

Rat trap in Cabinet 2

Phosphorus in hood

KClO3 in oxidizers cabinet

CS2 in Flammables cabinet


Acid-Base Chemistry

1.      Red Cabbage Indicator on pH 1, 4, 7, 10, 13 Buffers

 

Pureé red cabbage in blender with small amount of water; centrifuge, filter, or allow solids to settle. Use buffers in cabinet 3 and 0.1 M HCl, 0.1 M NaOH, in 150 mL beakers on overhead projector, You can also do a titration.

 

Borrow blender from Cooperman research group

Buffers in Cabinet 3

 

2.      Common Household Acids and Bases

 

Vinegar, lemon juice, windex, dishwasher detergent, soda, Drano, toilet bowl cleaner, etc.

 

Phenophthalein indicator, household acids &bases on Shelf A2

 

3.      Neutralize a Weakly Basic Solution (with Indicator) by Having Students Blow CO2

in with Giant Straws

 

Cabinet 2

 

4.      Dissolution of Marble Chips and limestone Chips in HNO3 or H2SO4 Solution: (Effect

of Acid Rain)

 

When marble of limestone chips are placed in strongly acidic solution, (e.g., 10-50% conc. HNO3 or H2SO4), they dissolve quickly. Dissolution in weaker acidic solution occurs, but requires more time(until the next class period.)

 

Stone chips in Cabinet 3

Acids beneath hood

 

5.      Ammonia Fountain

 

See under F8 on Page 14.


Redox Reaction and Electrochemistry

(Also see Thermochemistry Section)

 

1.      Place Piece of Sheets Copper in Concentrated HNO3

 

(Do under hood). Results in emission of brown gas and clear solution becoming blue.

 

Copper sheet on shelf E2

HNO3 in acids cabinet

 

2.      Put “Christmas Tree” of Sheet Copper in AgNO3 solution

 

Silver Plates out, copper dissolves giving blue solution.

 

AgNO3 solution in acids cabinet under hood

 

3.      Oxidation of Iodide by sodium Hypochlorite with starch Indicator.

 

Clear solution turns dark blue as iodine is produced.

 

NaOCl solution in acids cabinet

 

4.      Belousov-Zhabotinskii Reaction: Oscillations in Time and Space

 

A clear solution turns blue, then clear, etc. with a period of about 30 seconds, for a total time of about 50 minutes, (Note: Run the reaction in a 250 mL beaker in an overhead projector, mixing 50 mL of malonic Acid, 50 mL of 0.25 M KBrNO3, 50 mL of 6M H2SO4 and 1mL of ferroin indicator.)

 

5.      Electrolytic Decomposition of Water

 

A Na2SO4 solution is electrolyzed to produce H2 and O2. An indicator can be used to show the pH change in the solution around each electrode, An alternative method produces soap bubbles of gas that are explosive.

 

Hoffmann electrolysis apparatus on Desk D

Power supply on Desk B

Solution in Flammables Cabinet

 

6.      Electrolytic Decomposition of Brine

 

A NaCl solution is electrolyzed to produce H2, Cl2 and NaOH.

 

Hoffmann electrolysis apparatus on Desk D

Power supply on Desk B

 

 

7.      Electricity from a Fuel Cell

 

The fuel cell consist of two Ni gauze electrodes covered with platinum black separated by filter paper and sandwiched between plexiglass squares. When H2 and O2 are passed into opposite sides of the cell, the current is generated and will run a motor.

 

The fuel cell on Shelf C2

 

8.      Conductivity and Extent of Dissociation of Acids or Salts in Aqueous Solution

 

The strength of an Acid or the extent of dissociation of dissolved species can be illustrated by a conductivity tester. The lamp on the tester dose not light for distilled water, and only weakly in acetic acid or ammonium hydroxide, but strongly in mixtures of the two.

 

Cabinet 3

 

9.      Briggs-Rausher Reaction

Three colorless solutions are combined in a large beaker. The solution becomes amber, Then blue-back , the colorless again. This sequence repeats with a period of 15 sec. At 25oC.

 

10.  The Blue-Bottle Experiment: Reaction  of Oxygen with Glucose

 

A stoppered florence flask partially filled with a colorless solutions is shaken and quickly turns blue (or another color depending on the indicator). Upon standing the solution returns to colorless. Further shaking returns the blue color.

 

Indicators and glucose on Desk A and Shelf A


Solubility

 

1.      Loss of Volume When Absolute Ethanol and Water are Mixed

 

When two liquids are mixed, the volume of their solution is less than the sum of their individual volumes.

 

Food colors in Drawer B5

 

2.      Solubility of Lead Salts

 

Prepared 0.1 M solution of Lead Acetate, and Mix with 0.1 M Solutions of KNO3, K2Cr2O7, KCl

 

3.      Pipetting/Diluting a 1.0 M K2Cr2O7 Solution

 

Illustrate absorbance changes upon 1:10 or 1:100 dilutions.

 

4.      Deflating Styrofoam “Popcorn” with Acetone or Ethyl Acetate versus Deflating and

Dissolving Them in Methylene Chloride versus No Effect in Water

 

5.      Solubility of I2 in CHCl3 Layer Under Aqueous Layer

 

I2 in CHCl3 is in Inflammables cabinet

Separating funnel under cabinet A

 

6.      Conductivity of Solutions

 

See under E8 on page 13

 

7.      Measurement of Water Hardness

 

A titration of a Ca2+ standard solution and of tap water EDTA and calmagite indicator illustrates how water hardness is measured.

 

Ca2+ solution in flammables cabinet

Calmagite & EDTA in Cabinet 3

 

8.      Ammonium Foutain

 

A small amount of water is injected into an inverted round-bottom flask connected tby glass/plastic tubing to a reservoir of water below it. Soon after the injection, the water form the reservoir rushes up into the flask and turns red as it forms a fountain inside the flask.other color changes or luminol chemiluminescence upon injection are also possible.

 

Fountain apparatus on Desk D


Liquid Nitrogen and Oxygen

 

1.      Driving a Nail with Banana

 

Dewars under cabinet A

 

 

2.      Freezing Flowers, Racquet Balls

 

3.      Shrinking Balloons

 

Placing an air-filled balloon in liquid nitrogen results in a marked (and reversible) reduction in volume.

 

4.      Liquid Oxygen

 

Liquid O2 is collected by passing O2 from a cylinder through a condensing coil immersed in liquid nitrogen. The pale blue color of liquid O2 can be seen in a transparent Dewar flask. When poured between the poles of a magnet (on slightly-tilted sheet of plexiglass on an overhead projector), some is held in the gap until it evaporates, which is not seen for liquid N2.

 

Dewars under cabinet A

Condensing coil on Desk A

Magnet in Cabinet 3

 

 

 

 

 

 

 


Polymer

 

1.      Making Nylon 6-10

 

A film of nylon is formed at the interface between two immiscible liquids. When the film is lifted from the container, it is continually replaced, forming a hollow, continuous thread of polymer.

 

Flammables cabinet

 

2.      Making Polyurethane Foam

 

When two viscous liquids are mixed, a rigid foam is produced whose wolume is 20-30 times that of the original mixture.

 

Flammables cabinet

 

3.      Cuprammonium Rayon

 

When a blue solution containing Cu2+, NH3, and cellulose is injected into an acid bath, blue threads of rayon are formed.

 

4.      Classifying Recyclable Plastics

 

Samples of commonly recycled plastics are classifiable by density, melting and burning behavior, and halogen content (copper wire flame test).

 

5.      Making ‘Slime” (Polyvinyl alcolhol-Borax)

 

Two clear, colorless liquids are mixed and almost immediately gel. The gel can be formed into a ball, but if left unhandled, it flattens and runs.

 

6.      Phase Transitions of a Poly(acrylamide) Gel

 

When water is poured over a small quantity of white powder, it is gelled and thickens, becoming too thick to pour in less than a minute. Pouring NaCl on the gel returns it to a fluid state.

 

7.      Deflating Styrofoam “Popcom”

 

see under F4 on page 14.

 


Molecular Modes

1.      Crystal Lattices

 

Wurtzite, Diamond, Calcite I, Sodium, Chloride, Graphite, Copper, Aluminum, Cesium Chloride, Carbon Dioxide.

 

P-chem lab x-ray room

 

2.      Bravais Lattices

 

P-chem lab x-ray room

 

3.      Orbitals – VESPR theory

 

Construct from 12” round helium-quality balloons. Blow up six balloons to the same size. Tie pairs tightly together at the ends. Then assemble the 3 pairs together in an octahedral shape, tying the pairs together with string as close together as possible. By breaking the balloons one at a time, you should be able to get trigonal bipyramidal, tetrahedral, etc.

 

4.      Shell structure Model

 

Magnetized needles in corks in a water bath are surrounded by a 10-min coil of copper wire on overhead projector. Use power supply in cabinet 4 to supply 3 or 4 A @ Max. voltage to create a magnetic field. The needles are dropped in one at a time, producing a triangle (3), square (4), pentagon (5), hexagon (6), a hexagon with a second single needle “inner shell(7)”, etc.

 

5.      Model of wave Motion – Giant Plastic Slinky

 

Quantization is illustrated by oscillating the slinky at various frequencies to produce 0,1, 2, nodes.

 

6.      Large – Scale Darling Model Set

 

7.        Large – Scale Models of C2H6 and CO2


Miscellaneous

1.      Radioactivity: Geiger Counter and Uranium Salts

 

see Dr. Kent Blasie

 

2.      Periodicity: Cl2, Br2, I2 in Bulbs

 

Cl2, Br2, I2 under cabinet A

 

3.      Periodicity: Li, Na, K Metal in Water

 

Li, Na, K Metal in inflammable cabinet

 

4.      “Power of Ten” Film

 

Available from physics dept. demonstration lab

 

5.      Stereochemistry

 

The smells of R- and S- carvone are very different, although these molecules have mirror-image structure.

 

Inflammables cabinet

 

6.      Crook’s (electron beam) Tubes

 

on Desk B

 

7.      Colored Metal Complexes and Precipitates

 

By adding reagents, a number of metal ions form successively. These include Co(II), Pb(II), Ni(II), Ag(I), Cu(II), Fe(III), and Cr(III).

 

Ag(I) in Cabinet C4

 

8.      Onondaga Lake Water

 

The water of Onondaga Lake in New York has a fairly high concentration of ions such as Ca2+, Fe3+/Fe2+, Na+, Cl-, CO32-, and SO42- because of industrial pollution. A variety of tests can be made for these ions: conductivity before and after distallation of the “lake water”, flame tests for Na+, Fe3+, Ca2+, Cl-, and SO42-(using KSCN, sodium oxalate, Ag+, and Ba2+ reagents, respectively)

 

9.      High Temperature Superconductivity

 

A sample of Yba2Cu3O7-x superconductor placed on an inverted coffee cup will levitate a small SmCo5 magnet when cooled by pouring liquid N2 over it.

 

Superconductivity kit on Desk B