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November 9, 2010

ACS: Incorporating Green Chemistry into the High School Curriculum

Presented by: Michael Tinnesandand

Barbara Sitzman

ACS-NSTA Green Chemistry Web Seminar, November 9 2010

A. Pollution Prevention Act of 1990

B. The Presidential Green Chemistry Challenge of 1995

C. Oprah’s Favorite Things broadcast of 2002

D. The debut of Al Gore's An Inconvenient Truth in 2006

Quiz from the ACS Green Chemistry Institute http://www.chempower.org/quizintro.html

Which of the following events gave birth to today’s Green Chemistry Initiatives?


What is Green Chemistry?

Green Chemistry is the design of chemical products and processes that reduce or eliminate the use and/or generation of hazardous substances.


Green Chemistry is Benign by Design

When chemists plan, manufacture, process, use, and dispose of chemical products, they are making determinations about the impact on human health and environment .


Which of the following is NOT among the top 10 benefits of Green Chemistry?A. Energy efficiency B. Fuller, bouncier hair C. Less waste D. Improved environmental and human health


Principles of Green Chemistry1. Prevention2. Atom Economy3. Less Hazardous Chemical Syntheses4. Designing Safer Chemicals5. Safer Solvents and Auxiliaries6. Design for Energy Efficiency

© Paul T. Anastas and John C. Warner, 1998


Principles of Green Chemistry

7. Use of Renewable Feedstocks8. Reduce Derivatives9. Catalysis.10. Design for Degradation11. Real-time Analysis for Pollution Prevention12. Inherently Safer Chemistry for Accident Prevention© Paul T. Anastas and John C. Warner, 1998

Let’s pause for questions from the audience


Opinion Poll 1

• List one limitation to including Green Chemistry in a high school chemistry class.

[Type your ideas in the chat]


Barriers to Incorporating Green Chemistry in High School Courses

• The typical introductory chemistry course is already ‘full’. Lack control of your own curriculum.

• Beginning students can’t appreciate green innovations.

• Students confuse environmental with green chemistry.

• Green Chemistry can carry political baggage.

• Green Chemistry principles not applicable at high school level.

• New Greener labs could be expensive.


Opinion Poll 2• List one positive aspect of infusing Green

Chemistry in a high school chemistry class.

[Type your ideas in the chat]


Benefits of Including Green Chemistry in High School

Chemistry Courses• Improves academic labs that are not models of best

practice. • Cumulative effect of sustainable practices is great.• Students learn by example, important to set clear

priorities early. • Activities redesigned to replace current activities, but

with a ‘greener’ focus.• Activities and labs use commonly available supplies.• U.S. Students lag in understanding of topics relevant to

everyday life.


“…while a majority of students are aware of environmental issues, their understanding of the underlying causes of these issues lags behind their awareness…”

Mary Kirchhoff, Director, ACS Education DivisionJ. Chem. Educ., 2010, 87 (2), p 121


Green Chemistry can Reinforce Basic Chemistry Concepts

•Rates of reaction•Catalysis •Chemical cycles•Energy•Thermochemistry•Experimental design•Law of Conservation of Matter

•Stoichiometry•Percent yield•Solubility•Polarity•Phase change•Organic chemistry•Synthesis


Sample labs, demos and activities to Introduce Green Chemistry Principles

1. A convenient liquid CO2 extraction of natural products

2. Vitamin C clock reaction 3. Modeling atom economy4. Energy required to heat water


A Convenient Liquid CO2 Extraction of a Natural Product

The Royal Society of Chemistry publication, Green Chemistry.L.C. McKenzie, J.E. Thompson, R.Sullivan and J.E. Hutchison, Green Chem., 2004, 6, 355 - 358


A Convenient Liquid CO2 Extraction of a Natural Product


Green Lab - A Convenient liquid CO2extraction of a natural product

Chemistry Concepts:Solubility, polarity, phase change

Traditional lab:Solubility of polar and non-polar substances demonstrated by dissolving various combinations of nonpolar solutes and solvents

Green Chemistry Principle: Using safer solvents

The Green fix: Uses the preparation of liquid CO2 to demonstrate extraction of a nonpolar natural product using a green solvent.


Opinion Poll 3Do your students currently perform a solubility experiment?

Yes No

Is this lab an attractive substitute or addition?


A Clock Reaction with Safer Substances

•Solution B:•Hydrogen Peroxide•Starch Solution•Water

•Solution A:•Tincture of Iodine•Vitamin C from tablets•Water

Source: The Journal of Chemical EducationWright, Stephen W. The Vitamin C Clock Reaction, J.Chem. Ed., January 2002, 79 (1), p 41-43


Procedure for Clock Reaction


Iodine Clock Reaction Video



I2(aq) + C6H8O6(aq)-> 2H+(aq) + 2I-(aq) + C6H6O6(aq)

2H+(aq) + 2I-(aq) + H2O2(aq) ->I2(aq) + 2H2O(l)



Chemistry Concept: Rates of reaction

Traditional labs: A number of clock reaction labs using a varying degree of hazardous materials

Green Chemistry Principle: Using safer starting materials

The Green fix: Iodine Clock reaction using safer household materials


What if?Calculate the possible cumulative effect of not using safer materials.

A traditional clock reaction requires 150mL, 0.01 M HgCl2, per group of two students. If approximately 2 million introductory students in the U.S. did the safer experiment, how much mercury waste would be avoided?


Mercury calculation

Although it may be unlikely for every student in the U.S. to do the same experiment, the cumulative effect of using unsafe substances can still be significant!

2.0 ×106 students ×0.150L

2 students×

0.01mol Hg1L

×271.6gHg1 mol Hg

≈ 400,000g Hg


Opinion Poll 4Do you currently do a lab on rates of reaction in your course?

Yes No



Modeling Atom Economy

Calculate the Atom Economy for each reaction

Students use models to build 2-propene two different ways.


How to Calculate Atom Economy

Percent Atom Economy =formula weight of desired products

formula weight of all products× 100%





Reaction 1

Percent Atom Economy = 42g desired products119g total products

×100% = 35% atom economy





Reaction 2

Percent Atom Economy = 42g desired products60g total products

×100% = 70% atom economy


Modeling Atom Economy

Chemistry Concept(s):Law of Conservation of Matter, stoichiometry, percent yield

Traditional lab: Percent yield labs, stoichiometry

Green Chemistry Principle: The atom economy

The Green fix: Uses molecular models to introduce the concept of atom economy as an alternative/replacement to percent yield


Opinion Poll 5Do you currently ask students to calculate percent yield as part of labs in your course?

Yes No



Energy Required to Heat WaterCompare the efficiency in three methods of heating

Introduction to Green Chemistry, Ryan, M., Tinnesand, M., Eds. (pp. 45-53).


Energy Required to Heat Water

Chemistry Concepts:Energy, thermochemistry, experimental design, calorimetry

Traditional lab: Calculating specific heat capacity of substances. Measuring the heat of combustion using calorimetry

Green Chemistry Principle: Using lower amounts of energy in chemical processes

The Green fix: Comparing relative amounts of energy for heating substances in the lab


Energy Required to Heat Water

For each method of heating water we must do two calculations:1.The amount of heat produced by the source (Bunsen burner, hot plate, or microwave). 2.The amount of heat absorbed by the water.

The amount of heat absorbed, compared to the amount of heat produced by the source, is the efficiency of the heating method.


Heat Produced by Bunsen burner

Bunsen BurnerCombustion of methane takes 245 seconds (rate of flow = 19.9 x 10-3 L/s) to heat the water.

First, calculate the amount of heat released by the reactionCH4 + 2 O2 CO2 + 2H2O



The combustion reaction involves methane and oxygen combining to form carbon dioxide and water

CH4 + 2 O2 CO2 + 2H2O

Calculate the heat of reaction from standard heat of formation values. ΔHproduced by the reaction = (ΣΔH f products) − (ΣΔH f reactants)



ΔHproduced by the reaction = (ΣΔH f products) − (ΣΔH f reactants)

ΔHproduced by rxn = (CO2 + 2(H2O))− (CH4 + 2(02))

Here are the standard heat of formation values:

CO2 = -393.5kJ H20 = -241.8kJCH4 =-74.8kJ O2 = 0 kJ

CH4 + 2 O2 CO2 + 2H2O



ΔHproduced by the reaction = (ΣΔH f products) − (ΣΔH f reactants)

ΔHproduced by rxn = [−393.5kJ

mol+ 2(−

241.8kJmol

)]− [−74.8 kJ

mol+ 2(

0 kJmol

)] =−802.3 kJ

mol

ΔHproduced by rxn = [CO2 + 2(H2O)]− [CH4 + 2(02)]

Here are the standard heat of formation values:

CO2 = -393.5kJ H20 = -241.8kJCH4 =-74.8kJ O2 = 0 kJ

CH4 + 2 O2 CO2 + 2H2O



Bunsen BurnerCombustion of methane takes 245 seconds (rate of flow = 19.9 x 10-3

L/s) to heat the water.

CH4 + 2 O2 2H2O + CO2 Calculated ΔHproduced = -802.3 kJ/mol CH4

ΔH produced =heat of reaction

mol CH 4×

rate Ls

× time (s) ×1 mol CH 4

22 .4 L=



Bunsen BurnerCombustion of methane takes 245 seconds (rate of flow = 19.9 x 10-3

L/s) to heat the water.

CH4 + 2 O2 2H2O + CO2 Calculated ΔHproduced = -802.3 kJ/mol CH4

ΔH produced =heat of reaction

mol CH 4×

rate Ls

× time (s) ×1 mol CH 4

22 .4 L=

ΔH produced =−802 .3 kJ1mol CH 4

×19 .9 × 10 −3 L

s× 245 s ×

1 mol CH 422 .4 L

≈ 175 kJ


Energy Absorbed by the Water

Bunsen BurnerThe combustion heats 200.0 g H2O from 16.0°C to 66.5°C, ΔT=50.5°C

ΔHabsorbed = mass × Δ temp × specific heat capacity


Energy Absorbed by the WaterBunsen BurnerThe combustion heats 200.0 g H2O from 16.0°C to 66.5°C, ΔT=50.5°C

ΔHabsorbed = mass× Δ temp× specific heat capacity

ΔH absorbed = 200.0 g × 50.5°C ×0.00418 kJ

g × °C= 42.2 kJ


Heat Produced by Hot Plate and Microwave

The calculations for the heating by the hot plate and microwave oven are similar, the heat produced by the electric sources is easier to calculate if we know the wattage of the device. 1 watt = .001 kJ/second

ΔHproduced = wattageof hotplateor microwave×.001kJ

swatt

× Δ time


Heat Produced by Hot Plate

Hot Plate698 watt hot plate takes 378 seconds to heat 200.0 g H2O from 16.0°C to 66.0°C, ΔT=50.0°C

ΔHproduced = 698watt×.001kJ

swatt

× 378 s = 264 kJ

ΔH absorbed = 200 .0 g × 50.0°C ×.00418 kJ

g × °C= 41.8 kJ


Heat Produced by MicrowaveMicrowave1000 watt microwave takes 60 seconds to heat 200.0 g H2O from 18.0°C to 67.0°C, ΔT=49.0°C

ΔHabsorbed = 200.0 g × 49.0°C ×.00418 kJ

g × °C= 4 1.0 kJ

ΔHproduced =1000watt ×.001kJ

swatt

× 60 s = 60.0 kJ


Calculated EfficienciesCalculate efficiencies

Efficiency = ΔHabsorbed / ΔHproduced

Bunsen burner efficiency =42.2 kJ175 kJ

× 100 = 24.1%

hotplate efficiency =41.8 kJ264 kJ

× 100 =15.8 %

microwave efficiency =41.0 kJ60.0 kJ

× 100 = 68.3 %


Opinion Poll 6Do you currently do a lab that involves calorimetry in your course?

Yes No



ACS Green Chemistry Teaching Resources

• Introduction to Green Chemistry: Instructional Activities for Introductory Chemistry

• Real-World Cases in Green Chemistry, vol I and II• Going Green: Integrating Green Chemistry into the

Curriculum• Greener Approaches to Undergraduate ExperimentsACS .org/educationhttp://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_SUPERARTICLE&node_id=1444&use_sec=false&se

c_url_var=region1&__uuid=1c4c080f-cb10-4170-8115-86056b84a762


Journal of Chemical Education• Published by ACS for the ACS Division of

Chemical Education.

• Topics in Green Chemistry (edited by Mary Kirchhoff, ACS Director of Education) provides a forum for dissemination of the latest curricular developments in green chemistry.

http://jchemed.chem.wisc.edu/


Greener Education Materials for Chemists (GEMs)

• GEMs is an interactive tool developed by the University of Oregon.

• Organizes and disseminates core Green Chemistry educational materials.

• Searchable by level, keyword, topic, more…

•http://greenchem.uoregon.edu/gems.html


The Chemical Education Digital Library (ChemEd DL)

ChemEd DL aims to provide exemplary digital resources, tools, and online services to aid in teaching and learning chemistry.

http://www.chemeddl.org/

BibliographyACS Education Resourceshttp://www.acs.org/educationACS Green Chemistry

Resources http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_SUPERARTICLE&node_id=1444&use_sec=false&sec_url_var=region1&__uuid=1c4c080f-cb10-4170-8115-86056b84a762

Journal of Chemical Educationhttp://jchemed.chem.wisc.edu/Greener Education Materials for Chemists (GEMS)http://greenchem.uoregon.edu/gems.htmlChemical Education Digital Libraryhttp://www.chemeddl.org/

Thank you to the sponsor of tonight's Web Seminar:

http://learningcenter.nsta.org

http://www.elluminate.com

National Science Teachers AssociationDr. Francis Q. Eberle, Executive Director

Zipporah Miller, Associate Executive Director Conferences and Programs

Al Byers, Assistant Executive Director e-Learning

LIVE INTERACTIVE LEARNING @ YOUR DESKTOP

NSTA Web SeminarsPaul Tingler, Director

Jeff Layman, Technical Coordinator

acs: incorporating green chemistry into the high school ...acs-nsta green chemistry web seminar,...

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