PLAYCHEM
a series of
EXTRA CREDIT
Experiments
Short
Simple
Significant
http://genchem.rutgers.edu/PlayChem.html
ABOUT the
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PLAYCHEM
EXPERIMENTS
Experiment is individualized and run by computer.
Experimental work takes 15-30 min.
Calculations and conclusion take 15-30 min.
Data and calculations entered into computer.
Computer asks questions and grades student work.
Experiments are turned in.
Grades recorded using computer and student number.
Requires little or no instructor time.
Used as 20-25 pt EXTRA-CREDIT in Gen Chem Lab.
Five PlayChem experiments per semester.
6% of total points in our course.
Creating a
PLAYCHEM Experiment
1. Steal an idea
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5.
(J Chem Ed)
Modify to taste
Make it significant
Computerize
Try
PLAYCHEM EXPERIMENTS
1. ALCHEMY
2. ASPIRIN
3. AVOGADRO
4. BISULFATE
5. BLACKPEN
4. BREATHALYZER
7. CALIBRATE
8. CANCRUSH
7. CANDLELIGHT
10. DENPEN
11. DOBJECT
10. HYFORM
13. ICE
14. IVY
13. MILK
16. MOLRAT
17. MONEYCAL
16. MONEYCULE
19. MONEYKIN
20. ORG
19. PARADOX
22. POLLUTION
23. POPCORN
22. POTENTIAL
25. PUTTY
&
SLIME 26. REACT
28. SODACAN
29. STEELWOOL
31. ZERO
32. ZINC IODIDE
25. SOAP
30. VINEGAR
http://genchem.rutgers.edu/PlayChem.html
SteelWool
Burning SteelWool
in air and in
Oxygen
Calculate % weight change
Write chemical equation
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Weigh an assigned amount of Steel Wool.
Burn in Air and observe.
Weigh resulting residue.
Generate oxygen. (2 H2O2
O2 + H 2 O)
Repeat burning iron except in oxygen.
What happened? Why the difference?
MolRat
Mohr Titration
Ag+ + Cl2 Ag+ + CrO4-2
Drop-wise (Ag+ to Cl-) titration.
AgCl
Ag2CrO4
V x M = mmol
Using 0.10, 0.20 and 0.30 M NaCl and AgNO3 solutions
Assigning above solutions with “adjusted” concentrations
creates combining stoichiometries of
M3X M2X M3X2 MX M2X3 MX2 MX3
CanCrush
Charles’ Law - Kinetics
Vc/Tc = Vh/Th
Density of water = 1.00 g/cc
Pair remains constant (Ignore PH O)
2
Determine temperatures inside of soda cans.
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One is dry, the other contains a few mL of water.
Vh
Weigh “dry can”.
Heat both on a hot hot-plate until water boils.
Insert both, mouth down into a room temp water bath. Vc
Stopper opening of “dry can” and remove from bath.
Weigh.
Fill “dry can” with water and reweigh.
Read room temperature.
Determine temperature in each can.
MoneyCules
Mass of US Coins
Nickel = 5.0 g
Zinc and Brass Pennies
Mass of Dimes and Quarters are related
Plotting mass of coins vs dates
• Average Atomic Weight for a penny (zinc and copper isotopes).
• Counting value of “silver” coins by weighing.
• Creating a molecular structure from a set of coins.
• GREED Penny =1 Nickel = 2 Dime = 2 or 3 Quarter = 4
PUTTY
and
SLIME
Molecular Structure – Polymers - Physical Properties
• Partially hydrolyzed polyvinyl
acetate
• Guar Gum
Polymer solutions are viscous
• Compare weight % vs Molarity
Crosslink with BORAX
• Effects of long term stress
• Effect of sudden stress
• Reasons for the above
Possible uses for products
SOAP
HARDNESS of WATER
Previously carried out EDTA titration
Dropwise titration of hard
water using soap suds as
the end point
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Titrate equal amounts of two STANDARDS and an UNKNOWN.
Use distilled water as the BLANK.
Determine the average Titer, mg CaCO3/drop, of the soap.
Calculate the hardness of the WATER UNKNOWN.
Add a water softener and recheck hardness.
ICE
Heat of Fusion
of
DiHydrogen Monoxide
DHMO
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Styrofoam cup calorimeter with magnetic stirring bar
Computer assigned volume of hot water
Computer assigned calorimeter constant
Vernier LoggerPro© temperature probe
Add “dried crystalline DHMO”
Determine Heat of Fusion of DHMO
BreathAlyzer
400
500
600 nm
ABSORBANCE
Chromate
Cr(III)
Student is given an alcohol
STANDARD and a “Blood Sample”.
Student must determine if
Suspect is guilty of “Driving Under
the Influence”
BEER’S LAW
WAVELENGTH
3 CH3CH2OH + 16 H+ + 2 Cr2O7-2
C1/A1 = C2/A2
3 CH3CO2H + 11 H2O + 4 Cr+3
• Alcohol is oxidized by acid dichromate in boiling water bath.
• Concentration is determined by Cr(III) concentration.
• Spectroscopy using Beer’s Law at 580 nm.
DenPen
Density of a Penny
Mass
Volume
• Measure dimensions
• Measure water displaced
PLOTS
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Penny Mass vs Date
Penny Mass vs Volume
Penny Mass vs Number
Circumference/Diameter Ratio
Collects and displays multiple data.
Particular useful for High School.
ALCHEMY
Turning a coppery U.S. cent into a silvery then a golden penny.
• Heat a 1983+ penny in the flame. Isolate “penny guts”.
• Clean three pennies in salt and vinegar.
• Dry and weigh the cleaned coppery pennies.
• Boil pennies, “penny guts” in “butter of zinc solution.
• Reweigh silvery pennies.
• Convert one silvery penny to a golden penny.
• Measure the potential – “Penny Guts” vs penny.
• Calculate thickness of layer.
• Explain the process.
COOKBOOK
Pennies: oven roasted, pan
fried.
PLAYCHEM
a series of
EXTRA CREDIT
Experiments
Short
Simple
Significant
CONTACT: kluiber@genchem.rutgers.edu