Gary Bonomo
General Chemistry Lab Instructor and Supervisor
Syracuse University Chemistry Department
(Syracuse University Chemistry Department Home Page, 2015)
(SU Photo and Imagining, as cited by Syracuse University Archives, 2015)
CHE 107: General Chemistry Laboratory I
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Lab 03: Preparation and Viscosity of Biodiesel from Vegetable Oil
Lab 05a: Chemistry of Recycling Aluminum
Lab 05b: Synthesis of Alum from Clay
CHE 117: General Chemistry Laboratory II
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Lab 03: Vitamin C Clock Reaction
(Microsoft Office Clip Art, 2013)
Original Lab Provided by SUNY ESF
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Preparation and Viscosity of Biodiesel from Vegetable Oil
(Abrams, 2007; adapted from Clark et al., 2006)
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Permission granted to use this lab at Syracuse University
Modifications at Syracuse University
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Separation method of biodiesel and glycerol
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Relative Viscosity – modified to reuse same chemical reagents (less waste)
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Biodiesel product is used at Syracuse University
Biodiesel Synthesis
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Combine KOH pellets and methanol to make potassium methoxide
KOH (s) + CH3OH (l) ! K+ (aq) + CH3O– (aq) + H2O (l)
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Put canola oil in a beaker and heat in a water bath (50 °C)
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Add potassium methoxide solution to canola and bring temperature of
water bath to 65-70 °C (maintain temperature and stir for 45 minutes)
Triglyceride + 3 CH3O– ! 3 Biodiesel (Methyl Esters) + Glycerol
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Cool solution and use a separatory funnel to separate glycerol and biodiesel
(Abrams, 2007; adapted from Clark et al., 2006)
Relative Viscosity
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Four samples tested:
" B100 (100% biodiesel) at room temperature
" B100 (100% biodiesel) at ice bath temperature
" B20 (20% biodiesel, 80% petroleum diesel) at room temperature
" B20 (20% biodiesel, 80% petroleum diesel) at ice bath temperature
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Fill a 25 mL pipette above the 0 mL mark. Begin draining and time from
the 0 mL mark to the 23 mL mark. Drain back into sample container.
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Determine the relative viscosities by the following equation:
Relative Viscosity = Sample Time / B100 Room Temperature Time
(Abrams, 2007; adapted from Clark et al., 2006)
Biodiesel Synthesis
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How to prepare biodiesel fuel by transesterification
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Biodiesel is green alternative to fossil fuels
Relative Viscosity of Biodiesel
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How to calculate relative viscosity
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High viscosity and solidification of biodiesel at low temperatures
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B20 is a better alternative than B100 in cold climates
(Abrams, 2007; adapted from Clark et al., 2006)
First Part from SUNY ESF (Abrams, 2007)
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Students recycled aluminum to produce hydrogen gas (H2) and
KAl(SO4)2•12H2O (crystals of potassium alum)
Second Part at Syracuse University (Miller, 2013)
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Kaolin clay produces alum less expensively than starting from scrap Al
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Halloysite Nanoclay (H4Al2O9Si2 • 2 H2O) is used instead of Kaolin
(Al2Si2O5(OH)4), to avoid calcination of clay and sulfuric acid***
*** This is a safety choice for the classroom setting; still similar chemistry to the industrial process except with less heat and high cost clay
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Examine alternative recycling methods for aluminum instead of conversion
to alum (melt and forge into a new aluminum metal application)
Preparation
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Sample of aluminum foil is cutting into pieces (Al with polymer coating)
Forming K[Al(OH)4]
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3M KOH and light heating converts aluminum foil to K[Al(OH)4]
2 Al (s) + 2 KOH (aq) + 6 H2O (l) ! 2 K[Al(OH)4] (aq) + 3 H2 (g)
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Gravity filtration removes residual polymer coating
(Abrams, 2007)
Forming Soluble Al2(SO4)3
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9 M H2SO4 added to form precipitate of aluminum hydroxide Al(OH)3
2 K[Al(OH)4] (aq) + H2SO4 (aq) ! 2 Al(OH)3 (s) + 2 H2O (l) + K2SO4 (aq)
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Sulfuric acid dissolves Al(OH)3 to form soluble Al2(SO4)3
2 Al(OH)3 (s) + 3 H2SO4 (aq) ! 2 Al2(SO4)3 (aq) + 6 H2O (l)
Forming Alum Crystals
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Heat to dissolve; then cool in an ice bath and add a seed crystal:
Al2(SO4)3 (aq) + K2SO4 (aq) + 24 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s)
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Vacuum filter to separate, using 50 % ethanol to rinse
(Abrams, 2007)
Summary of Chemical Reactions:
2 Al (s) + 2 KOH (aq) + 6 H2O (l) ! 2 K[Al(OH)4] (aq) + 3 H2 (g)
2 K[Al(OH)4] (aq) + H2SO4 (aq) ! 2 Al(OH)3 (s) + 2 H2O (l) + K2SO4 (aq)
2 Al(OH)3 (s) + 3 H2SO4 (aq) ! 2 Al2(SO4)3 (aq) + 6 H2O (l)
Al2(SO4)3 (aq) + K2SO4 (aq) + 24 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s)
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2 Al (s) + 2 KOH (aq) + 4 H2SO4 (aq) + 22 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s) + 3 H2 (g)
(Abrams, 2007)
Forming Soluble Al2(SO4)3
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Add 5 M H2SO4 to clay, stir for 5 minutes, and store for 1 week
H4Al2O9Si2 • 2 H2O (s) + 3 H2SO4 (aq) ! Al2(SO4)3 (aq) + 2 SiO2 (s) + 7 H2O (l)
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Gravity filtration removes the silicon dioxide
Forming Alum Crystals
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Add K2SO4 and heat until the solution is boiling
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Cool in an ice bath and add a seed crystal:
Al2(SO4)3 (aq) + K2SO4 (aq) + 24 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s)
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Vacuum filter to separate, using 50 % Ethanol to rinse
(Miller, 2013)
Summary of Chemical Reactions:
H4Al2O9Si2 • 2 H2O (s) + 3 H2SO4 (aq) ! Al2(SO4)3 (aq) + 2 SiO2 (s) + 7 H2O (l)
Al2(SO4)3 (aq) + K2SO4 (aq) + 24 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s)
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H4Al2O9Si2 • 2 H2O (s) + 3 H2SO4 (aq) + K2SO4 (aq) + 17 H2O (l) ! 2 KAl(SO4)2 • 12 H2O (s)
(Miller, 2013)
Green Chemistry
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Comparison of methods for alum production:
Starting with scarp aluminum metal vs. Starting from Clay
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Comparison of methods for aluminum metal:
Melting of scarp aluminum metal vs. electrolysis of aluminum oxide
Lab Techniques and Calculations
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Gravity filtration and vacuum filtration
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Supersaturation and crystallization
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Limiting reagent, theoretical yield, and percent yield
(Abrams, 2007) and (Miller, 2013)
Green Chemistry in Higher Education Workshop
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Hosted July 2013 by beyondbenign
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Getting off to a good start: Using safer starting martials
(King, 2010; adapted from Wright, 2002)
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Produced a small amount of waste and low hazard waste
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Light on calculations, but explained general concept
Existing Lab in 2013
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Reaction Kinetics and Effect of Temperature (Luk, 2009)
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Produced a lot of waste and somewhat hazardous waste
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Detailed calculations, expand on the depth of the concept
Merging and Modifying of the Labs (Zheng, 2013)
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Cost savings in materials and smaller amount of waste generated
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Kept the detailed calculations and in depth data analysis
Article from beyondbenign (Cannon, 2015)
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Detailed case study highlighting the cost savings and waste reduction
between the 2009 lab (Luk) and the 2013 lab (Zheng)
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Waste disposal costs reduced from $333.05 to $82.25 per 500 students
Waste Disposal Cost Savings of $250.80 per 500 students
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Purchasing costs reduced from $977.30 to $136.00 per 500 students
Purchasing Cost Savings of $841.30 per 500 students
Solutions
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Beaker 1: Potassium iodide, starch, and sodium thiosulfate
potassium nitrate and ammonium sulfate used for dilutions rather than
DI Water to keep the same spectator ion concentrations (K+ and NH4+)
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Beaker 2: Ammonium persulfate
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Combine Beakers 1 and 2; stir and record time for the color to change
Concentration and Temperature
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Vary concentration of I– and S2O82–
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Vary temperature (ice bath, room temperature, hot water bath)
(Luk, 2009)
Run 3 is repeated in ice bath and hot water bath
Three Trials per each Run (15 Trials total)
(Luk, 2009)
Notable PostLab Questions
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Calculate the concentrations of the reactants when combined
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Calculate the reaction rates, orders of reaction, and rate law
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Calculate the rate constants for each trials
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For the three different temperature trials, graph ln k vs 1 / T
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Use the slope from the graph (– Ea / R) to determine the activation energy
(Luk, 2009)
Solutions
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Vitamin C solution: Vitamin C tablet dissolved in DI water with mild
heating and gravity filter to remove insoluble materials
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Solution A: Vitamin C solution, Lugol’s Iodine and DI water
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Solution B: hydrogen peroxide and liquid laundry starch
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Combine Solutions A and B; stir and record time for the color to change
Concentration and Temperature
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Vary concentration of hydrogen peroxide and Lugol’s Iodine
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Vary temperature (ice bath, room temperature, hot water bath)
(Zheng, 2013)
Trial 1 is repeated in ice bath and hot water bath
One Trial per each Run (5 Trials total)
(Zheng, 2013)
Notable PostLab Questions
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Calculate the concentrations of the reactants when combined
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Calculate the reaction rates, orders of reaction, and rate law
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Calculate the rate constants for each trial
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For the three different temperature trials, graph ln k vs 1 / T
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Use the slope from the graph (– Ea / R) to determine the activation energy
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Look up the procedure for the “Old Nassau Reaction” and compare
the procedure of this lab. Which is greener and why?
(Zheng, 2013)
Reagents:
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Do you have hazardous regents that have safer alternatives?
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Do have any unnecessary reagents?
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Can any reagents and supplies be used more efficiently?
Waste:
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Keep different wastes separate waste; easier for treatment later.
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Can any of the products be used by your lab or someone else?
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Collaborate with your school’s waste collection and processing staff!
Curriculum:
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Can any concepts be taught better through the lens of Green Chemistry?
1. Syracuse University Chemistry Department Home Page. http://www-che.syr.edu/ (accessed June 8, 2015).
2. SU Photo & Imaging, as cited by Syracuse University Archives. http://www-che.syr.edu/ (accessed June 8, 2015).
3. Office.com Clip Art. Microsoft PowerPoint (Version 2013). Microsoft Corporation.
4. Abrams, N. Preparation and Viscosity of Biodiesel from Vegetable Oil. SUNY ESF, 2007.
*Adapted from: Clark et. Al, 2006, J. Chem. Ed., 83 (2), 257-259.
5. Abrams, N. Chemistry of Recycling Aluminum. SUNY ESF, 2007.
6. Miller, C. Synthesis of Alum from Clay. Syracuse University, 2013.
7. King, J. Getting off to a safe start: Using safer starting materials for chemical reactions. Intro to Green Chemistry. 2010.
*Adapted from: Wright S., 2002, J. Chem. Ed., 79 (1), 41-43.
8. Luk, Y. Reaction Kinetics and Effect on Temperature. General Chemisty Laboratory II CHE 117 Lab Manual;
Second Revised Printing. Kendall Hunt Publishing. Syracuse University, 2009.
9. Zheng, H. Vitamin C Clock Reaction. Syracuse University, 2013.
10. Cannon, A. Vitamin C Clock Reaction, beyondbenign, 2015.
*Adapted from: “Getting off to a safe start – Using safer starting materials for chemical reactions” in
Introduction to Green Chemistry: Instructional Activities for Introductory Chemistry, ACS, 2002.