Chemistry: Exploring Students’ Understanding of the Relationship Between Acid-Base Conjugate Pairs and Their Relative Strength

Title: Exploring Students’ Understanding of the Relationship Between Acid-Base Conjugate Pairs and Their Relative Strength
Authors: Melissa W. Anderson, Nadia Carmosini, Katherine Friesen, and Yevgeniya Turov; Department of Chemistry, University of Wisconsin – La Crosse
Discipline/Field: Chemistry and Biochemistry
Submission Date: June 2013

Abstract: During our time working with students in CHM 104 [General Chemistry II], we have observed that concepts related to acid-base equilibrium are particularly challenging for students. Even after a significant amount of lecture and laboratory instruction, students still appear to have only a superficial understanding of the topic at the completion of the course. Therefore, the main goal of this study was to improve students’ understanding of the relationships between acids and bases and their conjugates, one of the most fundamental aspects of acid-base chemistry. This goal was approached by modifying the first lab experiment to deal with acid-base chemistry (Experiment #5). Students typically arrive to a lab period having skimmed the experiment procedure at best. Therefore, the instructor spends a significant amount of instruction time (~45 min) discussing the theory behind the experiment, as well as practical aspects of the lab. By removing the bulk of the pre-lab instruction out of the set experiment time (3 hours), and also asking students to complete work before they attended the lab, we hoped to focus their attention to the outcomes of the experiment having come to lab more prepared than in the past. Through this lesson study we found the modifications made to the experiment were useful in allowing the students to demonstrate their proficiency with equation writing skills, and also reinforced their understanding of many of the differences between acids and bases. However, common misunderstandings surrounding pKa, pKb, and pH we not fully addressed and still need some attention.

Lesson Study in Chemistry: Exploring Students’ Understanding of the Relationship Between Acid-Base Conjugate Pairs and Their Relative Strength (Full Report)

Chemistry and Physics: Capstone Lab in Rocketry Design

Title: Capstone Lab in Rocket Design
Discipline(s) or Field(s): Chemistry, Physics
Authors: Douglas Weittenhiller, Robert Koch, University of Wisconsin – Baraboo/Sauk County
Submission Date: August 17, 2007

General Physics l & ll is the calculus based Physics course taught at UW-Baraboo/Sauk County. This course presents the basic concepts of physics as they apply to mechanics, heat, wave motion, sound, thermodynamics, electricity, magnetism, light and nuclear physics.  It consists of lectures, discussion, and labs.  The lectures and discussions emphasize conceptual understanding as well as problem solving.  The labs use a hands-on, activity-based approach to learning physics concepts.  This course is designed for students whose program requires 1 year of physics or those who plan to take further courses in physics.  This project would allow the students to utilize their knowledge of mechanics and motion to design an aerodynamic rocket body to house a chemical motor and to calculate it’s max. altitude theoretically and compare the value to an experimental one.

General Chemistry l & ll is a one-year course in college chemistry.  It consists of lectures, discussion, and labs.  This course is designed for students whose program requires 1 year of chemistry or those who plan to take further courses in chemistry. This project would allow the students to utilize their knowledge of chemistry to fabricate a safe chemical motor.

Summary: The Physics students never did get to work with the Chemistry students as a team; however, they each individually designed a model rocket body to house a chemical motor propellant.  We also had (3) lectures/discussions pertaining to rockets. The 1st one was discussing the physics behind rockets- more in depth than the textbook material.  The 2nd one was an open discussion on how to calculate the max. altitude of a rocket theoretically and group work solving a sample problem similar to how we would do it during the lesson study. The 3rd meeting was a hands-on experiment launching a toy model rocket (no motor included) and then we used geometrical methods to determine the actual altitude of the rocket.

Chemistry and Physics Lesson Study: Capstone Lab in Rocketry Design (Final Report) 

Biology and Education: Enzyme Functions and Properties

Title: An Introduction to Biology Lab: Enzyme Functions and Properties
Discipline(s) or Field(s): Biology, Chemistry, Health, Medicine, Education
Authors: Kama Almasi, Lisa Bardon, Kurt Freund, Isabelle Girard, Eric Singsaas, University of Wisconsin-Stevens Point
Submission Date: August 15, 2007

Student Learning Goals: We have two different types of goals we hope to address in this lesson.  We have lesson-specific goals and we have a few goals that we hope to address throughout the course.  In our course goals, we emphasize improving our students’ comprehension of scientific concepts.  In the lesson goals, we focus on concepts relevant to how enzymes work.

General Biology Course Goals
Students will be able to:

  1. Express biological processes using mathematical, graphical, and visual form with figures.
  2. Improve oral and written communication skills
  3. Enhance collaboration skills
  4. Develop the following basic laboratory techniques: following a protocol, pipeting, measure  volume, timing, data recording, and graphing.
  5. Develop the parts of a scientific report: introduction, methods, results, and discussion.

Enzyme Function Lesson Goals
Students will be able to:

  1. Formulate a scientific question in terms of a testable hypothesis
  2. Discover the importance of enzymes in cellular metabolism
  3. Describe enzyme roles and how they relate to other biological aspects.  Example: How enzyme response to temperature determines where organisms can live on earth.
  4. Recognize and interpret nonlinear responses from their data
  5. Identify and correct misconceptions about biological functions, including: enzymes add energy, enzymes are “alive”, enzymes can “decide”, enzyme reactions are “on/off”.
  6. Define and apply the following vocabulary: enzyme, product, optimization, catalyst, protein, substrate, saturation, rate, and equilibrium.

Findings and Discussion: The lesson was a (3-hr) laboratory exercise on enzyme reactions. Students used simple materials tomeasure the rate of oxygen production from hydrogen peroxide in the presence of catalase, extracted from potatoes, which catalyzes this reaction. Once the students learned the basic measurement, they were asked to vary the concentration of enzyme, concentration of hydrogen peroxide, the temperature, and add an inhibitor. Students were asked to graph their results (e.g., relationship between temperature and oxygen production rate) for each experiment and to answer questions about the experiment, procedure, and results at each stage of the experiment. At the end of class, groups were asked to share their results with the class and discuss any differences between their results and other groups’ results.

As a result of information we gained during initial observation of the lesson, we substantially revised the protocol and lesson plan. In observations during labs using the revised protocol, we observed substantial improvements in students engagement with the material: student use of terminology increased, discussion of the topic material increased, student-instructor interaction increased, and attention to procedural details decreased.

The process of lesson study demonstrated to us, in a very dramatic way, how ineffective we are in assessing our lessons while we are teaching them. Although we were familiar with the end results of the unimproved lesson, we had not been able to determine the source of difficulties. Only when we were allowed to serve as observers – and not as instructors – were we able to devote the attention needed to listen to student conversations and understand the challenges. Afterwards, it was surprisingly easy in our group to generate ideas to address the inadequacies of our design.

The practice of teaching without observation or reflection now seems absolutely absurd. However, we have all agreed that our current teaching loads prevent us from applying our lessons from lesson study in any practical way.