Ground Level Ozone in Newton County, GA - ACS Publications

Chapter 7

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Ground Level Ozone in Newton County, GA: A SENCER Model for Introductory Chemistry Jack F. Eichler* Oxford College of Emory University, Department of Chemistry, 100 Hamill St., Oxford, GA 30054 *[email protected]

In an effort to implement a SENCER module into a first semester general chemistry course, a long-term air quality study has been initiated at Oxford College. This study, conducted in introductory chemistry courses for both science majors and non-science majors, is focused on the measurement of ground level ozone. As part of this project, students have created ozone detectors, helped design a long-term study that monitors local ground-level ozone, collected ground-level ozone concentration data at Oxford College, and created written reports that summarize both the general background information related to ground level ozone, as well as the data collected in class. This work, as well as preliminary assessment of the impact of this project on student attitudes and learning gains is described.

Introduction During the early part of my professional career as an educator, my philosophy of teaching focused on demonstrating my enthusiasm for chemistry to the students. The thought was that I could transfer my joy of the subject to the learner by overwhelming force. If they saw how much I loved chemistry and realized how “cool” it was, how could they not become enchanted? Perhaps in a way this may have worked; I believe I was considered a popular teacher by most of the students and they routinely did quite well on the end-of-course exams. However, after a couple of years passed by, I sensed that small groups of students did not buy into my excitement. This really disappointed me. If some of my students were not © 2010 American Chemical Society Sheardy; Science Education and Civic Engagement: The SENCER Approach ACS Symposium Series; American Chemical Society: Washington, DC, 2010.


learning to love chemistry, or at least begin to appreciate it, then what were they taking away from my class? My philosophy of teaching shifted then to not only demonstrating how interesting chemistry was, but began to also concentrate on having my course provide a set of skills that my students could use later in their lives. Even though they likely would not remember how to draw chemical structures or calculate the theoretical yield of a chemical reaction, perhaps they would take with them the ability to design a sound experiment or correctly analyze and interpret data. Therefore, even if a student did not develop a passion for the subject matter, at least s/he would gain some practical skills in my class. This approach helped provide a more meaningful reason to study chemistry, but I felt the general chemistry curriculum remained an abstract set of information for most students. Something was still missing. When I arrived at Oxford for my first full time position in higher education, I was quickly made aware of how I could make chemistry real and not remote to my students’ lives: the implementation of SENCER (Science Education through New Civic Engagements and Responsibilities). [For more information about SENCER, the reader is referred to www.sencer.net]. One of my colleagues in the chemistry department had developed a lab module for the non-majors general chemistry course that required the students to complete a water quality study, and I gladly adopted this lab module into my non-majors introductory chemistry courses (1). We did these lab activities in an effort to provide a more meaningful reason for learning chemistry, and this SENCER project was indeed quite successful in making chemistry relevant to our students’ lives and seemed to stimulate their intellectual curiosity much more than our traditional laboratories. In addition, the literature describing these types of projects suggested that though these activities do not necessarily “improve the ability of students to recall facts, it likely increases the ability to use evidence to support claims or to identify and solve complex problems (2).” It seemed that I had finally found that missing piece to my teaching philosophy. However, there were some limitations to the water quality study. Most of the water quality testing required the use of manufactured kits which did not clearly demonstrate the actual chemistry involved in the test, there was still some disconnection between the water quality at a local stream and the effect this might have on our students’ drinking water, and I was not sure this approach could easily be used in an introductory course for chemistry majors. In an effort to address these problems, I began to think about how I could refine the project in order to “SENCER-ize” my general chemistry courses for science majors. Luckily I stumbled across a paper by J.V. Seeley which described a simple method for measuring ground level ozone, the major component of photochemical smog (3). I felt air quality was a problem that had a much more direct impact on the students (we could measure the quality of the air they actually breathed), and the method of detection reported by Seeley required the students to use many of the chemistry concepts and skills learned in an introductory course. I decided this would be a convenient way to incorporate the SENCER ideals into both majors and non-majors general chemistry courses. 110 Sheardy; Science Education and Civic Engagement: The SENCER Approach ACS Symposium Series; American Chemical Society: Washington, DC, 2010.

I describe here a summary of how air quality has been used to frame the learning goals and outcomes in my general chemistry course for both majors and non-majors, an initial qualitative assessment of this program, and how it has impacted student learning and attitudes in my general chemistry courses.


SENCER-izing General Chemistry One of the arguments I have heard against implementing SENCER in courses intended for science majors is that incorporating a new project related to an unsolved civic issue will infringe upon the successful completion of the canonical course content. The appeal to framing the curricular content of our first semester general chemistry course around the issue of air quality lies in the fact the method reported by Seeley requires the students to apply most of the major concepts covered in this course. Table I summarizes the major concepts covered in our traditional general chemistry, those covered in our SENCER version of general chemistry, and those required to understand the concept of ground level ozone and how to complete the measurement of its concentration. It is clear that course content is not sacrificed, at least given the manner in which we teach general chemistry at Oxford College. The only material that is not covered in the air quality version of our course is the unit on organic nomenclature. This is a small sacrifice, as this is often not covered in our traditional course due to time constraints, plus this is material that will be thoroughly covered in more advanced chemistry courses. I also note the fact that almost all of the major concepts in the course are required to complete the ground level ozone study. The unit on thermochemistry is perhaps the farthest removed from the issue of air quality, but even this can be loosely tied to the ground level ozone project as one of the important chemical precursors to ground level ozone is produced in combustion reactions. [The formation of ground level ozone is dependent on the presence of nitrogen oxide compounds (NOx), which are primarily emitted from automobiles and fossil fuel combustion power plants. There are a variety of resources that describe in detail the formation of ground level ozone, but the reader may want to consult the reference book, Encyclopedia of global change: environmental change and human society (Andrew Goudie, editor, 2002, Oxford University Press, New York, New York) as a starting point.] I will not elaborate further on the details of how the concepts in this course are needed to complete the ground level ozone project, but will note that the report by Seeley, et al. will provide the reader with a nice summary of most of these topics. [The journal article by Seeley, et al. gives a detailed description of the aqueous chemical reactions involved in measuring ground level ozone, how standard solutions are prepared and used to determine the amount of ozone detected, and how the ideal gas equation is used to calculate the moles of air sampled.] In order to frame the course around the issue of air quality, a problem-based case study was done the first week of class. This case study was centered around a scenario in which someone blames their breathing problems on ground level ozone. The students were required to identify the major issues in the case and 111 Sheardy; Science Education and Civic Engagement: The SENCER Approach ACS Symposium Series; American Chemical Society: Washington, DC, 2010.

Table I. Major concepts covered in the traditional and air quality version of general chemistry, and those required to understand and calculate ground level ozone. General chemistry concepts that are not covered in the ground level ozone project are shown in bold. General chemistry concepts that are included in the traditional course but not in the air quality course are shown in italics


Traditional Course

SENCER Course

Ground Level Ozone Project

-measurement/data analysis



-atomic structure

-atomic structure

-atomic structure

-chemical bonding

-chemical bonding

-chemical bonding

-chemical reactions

-chemical reactions

-chemical reactions

-stoichiometry

-stoichiometry

-stoichiometry

-aqueous solutions

-aqueous solutions

-aqueous solutions

-gas laws

-gas laws

-gas laws

-intermolecular forces



-thermochemistry

-thermochemistry

-organic nomenclature

generate questions that needed to be answered in order to resolve the case. These questions were then documented, and acted as the content learning goals for the remainder of the semester. As the semester proceeded, the students were reminded about how each topic related to the problem of ground level ozone and how the specific content for each unit allowed them to answer some of the questions generated in the case study. At the end of the semester, three weeks were devoted to the problem of ground level ozone. The students completed research on the background information related to how ground level ozone forms, why it is a potential public health hazard, and how we were to measure it in lab. [Though few changes in the content of the lecture portion of the course were required, more significant changes in the lab schedule were needed to accommodate the ground level ozone measurement lab activities. In order to implement this project, the reader would need to consider that some labs may need to be eliminated.] We also did three labs where the students actually measured the concentration of ground level ozone on campus, and then all of the background information and new data were analyzed and summarized in a written report. Anecdotally, I have receive extremely positive feedback from the students, and representative comments from student reflective statements indicate that using this approach has been an effective way to engage the students in learning science (see Table II). Almost by consensus, comments indicate that this project

112 Sheardy; Science Education and Civic Engagement: The SENCER Approach ACS Symposium Series; American Chemical Society: Washington, DC, 2010.

was successful in helping the students achieve the course learning goals and a clear connection between chemistry and the students’ lives has been made.


Initial Assessment Overall, the SENCER-inspired air quality project seemed to have a positive impact on perceived student learning, on student attitudes towards science, and on student confidence in relating how science can be used to solve social issues. The comparison of pre- and post-course surveys indicates that the air quality SENCER module had an appreciably positive impact on the students’ perceived interest in discussing chemistry, and perceived confidence in solving problems, designing lab experiments, and understanding how science can be used to solve societal issues/problems. Gains were made in both the majors and non-majors courses, apparent by the increase in the average positive response on the post-course survey. There was an increase in the average response of at least 0.50 by the students in the majors course for the four selected questions, and the students maid particularly high gains in their confidence in solving problems and using science to solve societal problems (an increase in the average response was 0.80 and 0.64 for these two questions respectively; see Table III). The students in the non-majors course also made gains, as evidenced by an increase in the average response of at least 0.70 in three of the four questions. These students made particularly large gains in their confidence to design lab experiments and their understanding of how science can solve societal problems (an increase in the average for these two questions was 1.01 and 1.21 respectively; see Table III). It is also noted that a large number of students in both courses made at least some gains, as at least 55% of the students in the majors class reported gains in all four questions (70% reported gains in their ability to problem solve). The gains in the non-majors course were not quite as significant, as only 43% of the students reported gains in problem solving and in their understanding of how science can be used to solve societal problems. However, 64% of the students reported gains in their interest in discussing chemistry concepts and 78% reported gains in designing lab experiments (see Table IV). Future work will involve doing a more rigorous statistical analysis of the current, and subsequent survey data, as well as evaluating the results of American Chemical Society (ACS) end-of-course examinations for students taking general chemistry for science majors. The performance of our students will be compared to the at-large pool of ACS exam scores, and it is the hope that these future data will indicate that teaching the first semester general chemistry course with the air quality SENCER module does not dilute the content covered in the course. In fact, it is hypothesized this approach will reinforce the content.


Table II. Representative comments from student reflective statements concerning the effectiveness of using ground level ozone as a central theme in general chemistry Positive Remarks -“I think the ozone project was very helpful in completing the goals of this course. The ozone project gives purpose to almost all of the activities done in the class.“


-“This project was helpful in helping achieve the general course goals since it required one to learn the basics of chemistry and perceive its relevance to real world situations.” -“I enjoyed this project and I think that it has helped me to understand the importance of chemistry.” -“ The ozone study brought chemistry to life for me.” -“This project was something completely different from what I covered in AP chemistry, and allowed me to apply the chemistry knowledge to a completely new area.” -“…every skill we gained throughout the year was put to the test in the calculations to find the concentration of ground level ozone.” -“I do not see how a class period that does not have to do this project will be able to understand why chemistry is relevant to their life the way we do now.” Criticisms -“I wish there was a way to do the project at the beginning; I know it’s necessary to have all of the skills and understanding that is learned throughout the semester, but maybe seeing and getting the big picture and then working backwards toward a complete understanding of the topics would help.” -“I would have felt more satisfaction with the project had I been able to see the fruits of our labor put to use in some actual change in the local community.”

Conclusion I have described here a way to teach general chemistry for majors and nonmajors through the unsolved problem of air quality. This has enabled me to make a strong connection between science and the students’ lives, without sacrificing important curricular components that teach chemistry concepts needed for future courses. In addition, this approach has allowed me to teach non-majors most of the topics covered in the major’s course (unlike many “science appreciation” courses). Incorporating the SENCER ideals into my introductory chemistry courses has allowed me to not only help develop the critical thinking and problem solving skills in my students, but it has allowed me to clearly demonstrate to my students why they have a vested interest in learning chemistry and contributed to increasing the students’ interest in science. Results from pre- and post-course surveys, as well as free response reflective statements indicate that students feel they have achieved the course goals and made gains in acquiring new skills, particularly problem solving, experimental design, and using scientific knowledge to solve social problems. Given these outcomes, I feel confident that this approach will continue to be an effective approach to teaching general chemistry for both science majors and non-majors, 114 Sheardy; Science Education and Civic Engagement: The SENCER Approach ACS Symposium Series; American Chemical Society: Washington, DC, 2010.

Table III. Results from selected survey questions, and representative comments from student reflective statements concerning course outcomes and the effectiveness of the SENCER module. Responses from the survey are given as the average value of the responses from a 1-5 Likert scale, along with the number of students who responded 4 (a lot) or 5 (a great deal) per total number of student respondents (given in parentheses) Majors

Non-majors


Pre-Course Question 1. I am interested in discussing chemistry with friends or family.

3.10 (7/20)

3.0 (7/18)

2. I am confident I can solve problems.

3.20 (9/20)

3.33 (8/18)

3. I am confident I can design lab experiments.

3.20 (9/20)

2.78 (4/18)

4. I am confident I can understand how science can be used to help solve societal problems/issues.

3.16 (7/20)

2.65 (3/18)

1. I think I will carry with me the ability to discuss chemistry concepts with me the ability to discuss chemistry concepts with peers and others.

3.60 (12/20)

3.71 (9/14)

2. This course has added to my skills in problem solving.

4.0 (14/20)

3.5 (7/14)

3. I am confident I can understand how scientific experiments are designed.

3.70 (13/20)

3.79 (9/14)

4. I am confident I can understand how scientific knowledge can be used to help address societal problems.

3.8 (15/20)

3.86 (8/14)

Post-Course Question

Table IV. The number of students who made gains in questions 1-4 (the number of students who reported some improvement from the pre-course question on the post-course question is reported) Question

Made gains (majors)

Made gains (Non-majors)

1.

11/20 (55%)

9/14 (64%)

2.

14/20 (70%)

6/14 (43%)

3.

13/20 (65%)

11/14 (78%)

4.

12/20 (60)

6/14 (43%)

and that educators in all fields of science should consider teaching their introductory courses using the SENCER model.


References 1.

2.


3.

Patrick, H. R.; Ali, M. M.; Harmon, B. B. Forming Bonds: Chemistry and Community. In Abstracts of Papers; 225th ACS National Meeting, New Orleans, LA, March 2003. Ash, S. L.; Clayton, P. H.; Atkinson, M. P. Integrating reflection and assessment to capture and improve student learning. Michigan Journal of Community Service Learning 2005 (Spring), 49–60. Seeley, J. V.; et al. A simple method for measuring ground level ozone in the atmosphere. J. Chem. Educ. 2005, 82 (2), 282–285.


Ground Level Ozone in Newton County, GA - ACS Publications

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