The POGIL Method Workshop

1
The POGIL Method Workshop

• Stefanie Paternostro
• Terry Biondo

2
POGIL Background

• Process Oriented Guided Inquiry Learning
• Students in small groups working through
  activities
• Content learning
• Piaget
• Learning Cycle
• Induction Deduction
• E ? I ? A
• Exploration Concept Invention Applicati
  on

3
A POGIL Classroom
4
Efficacy of POGIL
POGIL General Chemistry at Franklin Marshall
College
8 years of data (n 905)
Lecture
POGIL
D, W, F Drop, Withdraw, Fail A, B, C Grades
Earned
Data from classrooms of Moog, Farrell and Spencer
Chi-squared 40.9 alpha lt 0.005
Farrell, J.J. Moog, R.S. Spencer, J.N. J. Chem.
Educ. 1999, 76, 570.
5
Structure of an Activity

• Introduction for the facilitator
• Engage the student
• Model
• Questions based on Piagets learning cycle
• Exercises

6
Developing a Model

• Focus Clarity
• Acceptable Forms
• Tables
• Equations
• Diagrams
• Sets of written relationships
• Short reading passage
• Pictures

7
Following the Learning Cycle

• Explorative questions
• Observations from model/previous knowledge
• Concept Inventive questions
• Observation Observation concept
• Discussion
• Application
• Concepts in action

8
Excerpt from Activity 1For the Teacher

• Why?
• Acids and bases are used in everyday life in a
  variety of places our bodies use acids to aid in
  digestion acids are used in the power cells of
  batteries and many ingredients in cooking have
  either acidic or basic properties.

9

• Learning Objectives
• Understand Arrhenius Acids and Bases
• Understand reactions of Arrhenius Acids and Bases
• Understand Brønsted-Lowry Acids and Bases
• Understand reactions of Brønsted-Lowry Acids and
  Bases

10

• Success Criteria
• Compare Arrhenius Acids and Brønsted-Lowry Acids
• Compare Arrhenius Bases and Brønsted-Lowry Bases
• Explain the relationship between Brønsted-Lowry
  Acids and Bases
• Identify these acids and bases in reactions

11

• Prerequisites
• Understand parts of a chemical reaction (i.e.
  products and reactants)
• Have a familiarity with ions

12
Excerpt from Activity 1Engaging the Student
Have you ever sucked on a lemon to get rid of
your hiccups? If you have, did you stop to
wonder why the lemon was sour?
The answer is in the acid which the juice
contains! And while these acids taste sour, bases
taste bitter.
13
Excerpt from Activity 1Model
Model 3 Reactions of Brønsted-Lowry Acids
Model 4 Reactions of Brønsted-Lowry Bases

• 15. How do Brønsted-Lowry Bases relate to
  Brønsted-Lowry Acids?
• They are the reverse reactions of
  one-another.

14
Excerpt from Activity 1Exploration Questions

• Model 1 Dissociation Reactions of Arrhenius
  Acids
• 1. What type of reactions are these?
• 2. What do the products of each of these
  reactions have in common?

They are dissociation reactions.
Each reactant yields a hydrogen ion.
15
Excerpt from Activity 1 Concept Invention Question

• Question 3 The acids pictured in Model 1 are
  all Arrhenius Acids. Based on the dissociation
  reactions of these acids, define an Arrhenius
  Acid.
• Answer 3 Arrhenius Acids yield hydrogen ions.
• Question 9 HCl, HF, and HSO4- are all
  considered Brønsted- Lowry Acids. Given your
  observations of the reactions above, define
  Brønsted-Lowry Acids.
• Answer 9 Brønsted-Lowry Acids yield hydrogen
  ions.
• 10.Based on your answers to questions 3 and 9,
  explain any differences or similarities between
  Brønsted- Lowry Acids and Arrhenius Acids.
• Both yield hydrogen ions.

16
Excerpt from Activity 1 Exercise (Application)

• C6O7H8, a component of citric fruit juices,
  would dissociate to form C6O7H7- and H ions.
  Explain how this accounts for the taste of many
  citric fruits.

Since C6O7H8 is yielding an H, it is an acid,
which we learned earlier tastes sour. This makes
sense because citric fruits often taste sour
(i.e. lemons and grapefruits).
17
Excerpt from Activity 2AEngaging the Student

• We all know lifeguards save lives by learning
  how to rescue victims from the water and perform
  CPR, but did you know they have to also
  understand chemistry? Its true! The water in a
  swimming pool must be kept neutral in order to
  keep swimmers safe. Have you ever seen the pH
  bottles with their little color guide? Have you
  ever wondered how they work?

18
Excerpt from Activity 2AModel
Model 2 pH Scale
Taken from de Dios, Angel C. Home Page of Angel
C. de Dios. bouman.chem.georgetown.edu/S02/lect14/
ph.gif (accessed 14 Apr 2008), Lect 14.
19
Excerpt from Activity 2AExploration Questions
Model 2 pH Scale

• According to Model 2
• A) What is the approximate pH of cola?
• B) What is the approximate H of cola?

3
1 x 10-3
20
Excerpt from Activity 2A Concept Invention
Questions
Model 2 pH Scale
Question What do you notice about the exponents
of the hydrogen ion concentration and their
relationship to the pH?
pH -log H
21
Excerpt from Activity 2AExercise (Application)

• The following are the more precise pHs of
  several household items. Use the pH equation to
  calculate their H.
• Household Item pH H
• Milk 6.5
• Lemon Juice 2.5
• Milk of Magnesia 10.5

3.16 x 10-7 3.16 x 10-3 3.16 x 10-11
22
Excerpt from Activity 2BEngaging the Student

• Now that we know how to determine how strongly
  present an acid or base is in aqueous solution,
  lets figure out how to determine strength out of
  solution. What if the acid or base is pure? How
  do we know how strong it is?

More of a bridge from Activity A to Activity B
23
Excerpt from Activity 2BModel
Model 1 Dissociation Reactions
Table 1 Acid Dissociations and Concentrations
Acid Concentrations Concentrations Concentrations Ka
H2C2O4 H2C2O4 1.00 M HC2O4- 0.24 M H 0.24 M
H2PO4- H2PO4- 1.00 M HPO42- 6.93 x 10-7 M H 6.93 x 10-7 M
H2CO3 H2CO3 1.00 M HCO3- 6.56 x 10-4 M H 6.56 x 10-4 M
24
Excerpt from Activity 2BExploration Question
Table 1 Acid Dissociations and Concentrations
Acid Concentrations Concentrations Concentrations Ka
H2C2O4 H2C2O4 1.00 M HC2O4- 0.24 M H 0.24 M
H2PO4- H2PO4- 1.00 M HPO42- 6.93 x 10-7 M H 6.93 x 10-7 M
H2CO3 H2CO3 1.00 M HCO3- 6.56 x 10-4 M H 6.56 x 10-4 M
Looking at Table 1 A) What is the
concentration of hydrogen ion produced by the
dissociation of H2C2O4? B) What is the
concentration of conjugate base (HC2O4-) produced
by the dissociation of H2C2O4? C) What
is the concentration of acid H2C2O4?
0.24 M
0.24 M
1.00 M
25
Excerpt from Activity 2BConcept Invention
Question
14. Using your answers to questions 12 and 13,
circle the correct answer. pH is
(proportional/inversely proportional) to
Ka. 15. What does your answer to question 14
mean about the strength of an acid in
relationship to its Ka? The higher the Ka, the
stronger the acid.
26
Excerpt from Activity 2BApplication Question
Table 1 Acid Dissociations and Concentrations
Acid Concentrations Concentrations Concentrations Ka
H2C2O4 H2C2O4 1.00 M HC2O4- 0.24 M H 0.24 M
H2PO4- H2PO4- 1.00 M HPO42- 6.93 x 10-7 M H 6.93 x 10-7 M
H2CO3 H2CO3 1.00 M HCO3- 6.56 x 10-4 M H 6.56 x 10-4 M
5.76 x 10-2 4.80 x 10-13 4.30 x 10-7
10. Using your answers from questions 6, 7, and
8, calculate the Kas of the acids listed in
Table 1 and write your answer in Table 1 under
the column labeled Ka.
27
Excerpt from Activity 3BEngaging the Student
The answer comes in a type of reaction called the
oxidation-reduction or redox reaction. This
reaction is a process which turns the copper from
that shiny color of the penny we know so well, to
the blue-green color of the Statue of Liberty!
Redox!
28
Excerpt from Activity 3BModel
Model 1 1st Definition of Redox Reactions
Reduction Reactions
Oxidation Reactions
29
Excerpt from Activity 3BExploration Questions
Model 1 1st Definition of Redox Reactions
Reduction Reactions
Oxidation Reactions
1. Under the reduction reactions of Model 1,
what are the products of A) the reduction of
CO? B) the reduction of SO2? C) the
reduction of 2NO2?
2. Using your answers to question 1, what do the
reduction reactions of Model 1 have in common? An
O2 molecule is produced in each reduction
reaction.
2C and O2
S and O2
N2 and 2O2
30
Excerpt from Activity 3BConcept Invention
Questions

3. Using your answer to question 2, fill in the
blank for the first definition of reduction
reactions. A reduction reaction results in the
loss of an oxygen molecule.
31
Excerpt from Activity 3BExercise (Application)
Label the following half reactions as oxidation
or reduction and list the rule being
followed. Oxidation/Reduction
Rule
oxidation
loss of e-

reduction reduction in
oxidation number
32
Acknowledgements

• Chestnut Hill College
• Dr Butler, Advisor
• Franklin Marshall College
• Rick Moog
• Jim Spencer
• Washington College
• Frank Creegan
• Cheltenham High School
• Donna Reinhart