Teaching Inquiry-Driven
Organic Chemistry Labs
Jerry Mohrig
Carleton College
Northfield, MN
Introduction and
Workshop Objectives
Summer 2006
• Provide the participants hands-on experience with questiondriven, guided-inquiry organic chemistry projects and
experiments.
• Allow the participants to evaluate what works well for guidedinquiry and design-based experiments and what are the practical
constraints.
• Help the participants learn how to invigorate their laboratory
courses by using inquiry-driven experiments and projects.
• Provide the participant experience with recasting a traditional
experiment or project into a question-driven or design-based one.
• Encourage sharing of positive and negative experiences by
participants regarding their teaching of organic chemistry labs.
• Explore whether graduate-student teaching assistants can provide
competent supervision in the use of inquiry-driven organic
chemistry labs and what training will be necessary to do this
successfully.
Two Important Questions
Why Do We Teach Labs?
What Are Our Goals In
Teaching Organic Chemistry Labs?
Traditional Lab Teaching Goals
• Teach students how to follow experimental
directions
• Allow students to verify what the lab manual says
Higher-Order Traditional Lab Goals
• Help students experience the material taught in
our lectures and deepen their understanding of it
• Teach modern laboratory techniques to students
• Teach students to synthesize organic compounds
The Important
“Non-Traditional Goals”
of Laboratory Teaching
• To teach students how to interpret experimental
results and draw reasonable conclusions
• To teach students how to design their experimental
procedures
• To encourage students to ask questions and find
answers
• To allow students to explore the process of science
Styles of Lab Teaching
Traditional
Verification Experiments
Provide confirmation of knowledge that students have been asked to learn
Make a white powder, prove it’s what you expect, and donate it to chemical
waste, again and again – giving the word “cookbook” a bad name
Inquiry Driven
Guided-Inquiry or Discovery Experiments/Projects
Question driven
Outcome not known but the chemistry builds on what the students have
studied - experimental results must be evaluated and conclusions drawn
A procedure is often given
Design-Based Experiments/Projects
Adapting generic procedures to synthesize target compounds
Students make decisions on the design of experimental procedures and
learn the consequences of their choices
Open-ended Inquiry Experiments/Projects
Students generate their own procedures and investigate the outcomes
Traditional Grignard
Synthesis Project
H2SO4/H2O
H3C
OH
NaBr
H3C
Br
H3C
MgBr
Mg
H3C
Br
ether
O
H3 C
OH
C4H9
H3C
H2O, H+
CH2CH3
CH2CH3
Design-Based Grignard Project
Purpose: To design and carry out the Grignard synthesis of a secondary or
tertiary alcohol from a simpler primary alcohol
R
OH
H2SO4/H2O
NaBr
R
Br
Mg
ether
R
MgBr
R = C3H7, C4H9, C5H11,
(CH3)2CHCH2CH2
O
OH
R
R'
MgBr
R''
R' = CH3, CH2CH3
R'' = H, CH3, CH2CH3
H2O, H+
R
R'
R''
Traditional Acetylation of
Ferrocene
O
C
CH3CO2COCH3
Fe
Fe
H3PO4
ferrocene
acetylferrocene
Guided-Inquiry Diacetylation of Ferrocene
Question: Which diacetylferrocene isomers form?
O
C
CH3COCl
Fe
Fe
AlCl3, CH2Cl2
ferrocene
acetylferrocene
O
O
O
C
Fe
O
O
O
C
C
C
C
or
Fe
or
Fe
C
1,1'-diacetylferrocene
mp 127
1,3-diacetylferrocene
mp 188
1,2-diacetylferrocene
mp 97
The Advantages of Multi-Week
Projects
• Promote student engagement and ownership
• Break out of the straightjacket by allowing flexible
use of lab time
• Can utilize any pedagogy and are effective at all
educational levels
• Promote guided-inquiry instruction
• Can use organic synthesis in the context of asking
questions
• Provide good teamwork opportunities
• Allow lower lab costs
Keys to Success in Using
Inquiry-Driven Labs
Teaching the Art of Data Interpretation and
Experimental Design
• Communication of the lab goals and methods to all
concerned
• Faculty participation
• Providing time for pre- and post-lab discussions
• A range of inquiry-driven experiments and projects,
from the straightforward to the sophisticated
• Availability of some modern instrumentation
• Availability of suitable written background materials
Suitable Written Background
Materials
A clear well-defined question or purpose, stated up front
Background material so that students can successfully
interpret their experimental data
Clear, student-friendly experimental directions or models
for developing them
A well-written techniques book, which contains modern
spectroscopy as well as traditional lab techniques
Summary
Inquiry-driven experiments and projects
are effective:
• For allowing students to make hypotheses based
on what they have learned in the classroom
• For teaching students how to evaluate their
experimental data and draw conclusions from
them
• For helping students to learn how to design and
carry out experimental procedures
• For allowing students to experience first-hand the
science of organic chemistry