Transcript POGIL Laboratory Experiments

POGIL Laboratory Experiments
Place
Date
Facilitator(s)
Activity 1:
Your Laboratory Experiences
• Take out a piece of paper
• Divide the paper in half, labeling one half
“Successful” and the other half “Horrible”
Consider All Your Laboratory Experiences
as a Student and as an Instructor
Individually:
• Identify a specific course-related laboratory
experiment that was very successful, describe the
experiment, and list three things that made it
“successful.”
• Identify a specific course-related laboratory
experiment that was horrible, describe the
experiment, and list three things that made it
“horrible.”
(3 min)
Common Laboratory Experiences
• Discuss your “successful” and “horrible’ laboratory
experiments within your group. Try to find any
common characteristics.
• Identify three significant characteristics
(preferably that you have in common) for the
successful experiments and three significant
characteristics for the horrible experiments.
• Be prepared to report out your list.
[7 min]
Reporting Out
Activity 2:
A POGIL Laboratory Experience
Question of the Day:
How is the structure of a molecule related to its boiling point?
Boiling point can be thought of as a measure of the strength of
attractions between molecules in a liquid.
Some potentially useful information
Compound
octane
2-butanol
Molecular
Formula
Structural Formula
MW
BP (oC)
C8H18
114
126
C4H10O
74
100
Question of the Day:
How is the structure of a molecule related to its boiling point?
Boiling point can be thought of as a measure of the strength of
attractions between molecules in a liquid.
• Individually list five relationships between molecular structure and
boiling point. (e.g., the larger the X, the higher the boiling point; the
more Y, the higher the boiling point; the longer the name, the higher
the boiling point, etc).
[2 min]
• Within your group your manager will lead a discussion of your lists
and the preparation of a prioritized list of these relationships. Your
presenter will be called upon to report out your results.
[3 min]
Question of the Day:
How is the structure of a molecule related to its boiling point?
Reporting Out
Question of the Day:
How is the structure of a molecule related to its boiling point?
Typical student responses
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Molecular weight
Shape
Size
Kind of atoms
Strength of bonds
Number of atoms
Number of bonds
Types of bonds
• What experiment(s) would need
to be conducted to test these
hypotheses?
• What apparatus and what reagents
would be needed?
Boiling Points of Liquids
Group #1
Group #2
Group #3
(hydrocarbons
of varying length)
(hydrocarbons of varying
length with OH)
(hydrocarbons of varying
length with C=O)
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pentane
hexane
heptane
decane
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1-propanol
1-butanol
1-pentanol
1-hexanol
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acetone
butanone
3-pentanone
2-heptanone
Group #4
Group #5
Group #6
(4 or 5 carbons; 1st 3
nearly identical MW)
(5 or 6 carbons; last 3
almost identical MW)
(first pair, last pair:
almost identical MW)
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pentane
1-butanol
butanone
1-pentanol
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pentane
hexane
3-pentanone
1-pentanol
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acetone
1-propanol
3-pentanone
1-pentanol
Analysis of Your Group Data
• Examine the data in your group and determine
if there are any trends. If so, discuss what
those trends mean.
• Which one of the possible hypotheses seems
most likely based solely from your group data?
• Which of the possible hypotheses can be
rejected based solely from your group data?
[5 min]
Analysis of Group Data
Analysis of Group Data
Analysis of Group Data
Analysis of Group Data
Possible Further Extensions
• Use molecular modeling to investigate relationship of
structure to dipole moments and boiling point.
• Predict (and measure) the boiling points of other liquids.
• Note that 2-butanol (100°) and 1-butanol (112°) have
different boiling points. Is this a general difference
between 1- and 2- alcohols? How does placement of the
OH group influence boiling point?
Student Outcomes
As a group:
Identify one laboratory skill that is developed
and one content learning objective for the
boiling point experiment.
[2 min]
The POGIL Laboratory Experience
What distinguishes a POGIL laboratory experience
from a traditional laboratory experience?
The Traditional Laboratory
In many traditional laboratory settings, a
concept that has been previously introduced in
class, or presented as part of the pre-lab
preparation, is confirmed or verified through the
“experiment.”
Distinguishing Characteristics
of “Verification” Laboratories Identified
by College Chemistry Students
• The instructor is concerned with the correctness of data.
• The instructor lectures the whole class.
• During laboratory the students record information
requested by the instructor
• The laboratory experiments develop skill in the techniques
or procedures of chemistry.
• Students usually know the general outcome of the
experiment before doing the experiment.
Abraham, M.R. (1982). A descriptive instrument for use in investigating science
laboratories. Journal of Research in Science Teaching, 19(2): 155–165
The POGIL Laboratory
• Laboratory work is performed in advance of classroom
work on underlying principles (limited background).
• Students work in self-managed teams to conduct
experiments rather than exercises that verify previously
taught principles.
• During a pre-lab session (real and/or virtual) the
instructor poses a focus question or Question of the Day
(QOD) and students propose a set of tentative answers.
• Students do NOT all perform the identical experiment
• Data is combined from multiple students to uncover
general trends or concepts, and address the QOD.
Pre-Lab Session
• Provides focus and structure; gets everyone involved
• Focus question (Question of the Day)
• Solicit hypotheses or predictions from students
• Discuss appropriate experiments
What is expected for each hypothesis
Data Collection
• Students collect data, with different students measuring
related phenomena but with appropriate variations to
address the QOD.
• Guided inquiry questions during the data collection phase
may help students think about the implications of their
results.
• Some duplication of conditions between students can be
desirable to check for reproducibility and reliability of
results.
Data Analysis
• Students may attempt to address the QOD and their
hypothesis from their own data, but eventually a
compilation of all data is used to reach final conclusions.
• Guided inquiry questions during the data analysis phase
can help students uncover the intended relationships and
concepts.
• Some application of the newly developed concept is
undertaken—possibly as a follow-up laboratory experience
The Learning Cycle*
• Data Acquisition
• What did you do?
• Is there any
pattern in the data?
• What did you find?
• What does it
mean?
• Apply developed
concepts
• Test hypotheses
• Higher level of
thinking
* Karplus and Thier, A New Look at Elementary School Science, Chicago: Rand
McNally (1967); Piaget, Journal of Research in Science Teaching 1964, 2, 176.
Boiling Point Experiment and the
Learning Cycle
As a group:
• Identify which components (if any) of the
experiment correspond to each phase of the
Learning Cycle.
• Does the boiling point experiment that you
worked through follow the Learning Cycle?
[2 min]
POGIL Laboratory Criteria
Activity 3
Is This a POGIL Experiment?
• Read through this melting point experiment
• Identify whether or not each of the required
criteria is met (or is likely met) by this
experiment.
• Conclude whether or not this is a POGIL
experiment
[5 min]
POGIL and SWH:
Science Writing Heuristic
SWH
POGIL
Students write their own question
Provides the question
Creates student-centered learning
environment
Creates student-centered learning
environment
Required to have student input in the design
of experiments
Desirable to have student input in the design
of experiments
Analyze data and discuss as group
Analyze data and discuss as group
Uses the SWH lab notebook format
Uses the traditional lab notebook format
Students as a group experience conceptual
negotiation
Instructor guides students to appropriate
conclusion
Emphasis on reflective writing in the
notebook
Guides students to think about what has
been learned (in-lab and post-lab questions)
http://avogadro.chem.iastate.edu/SWH/homepage.htm