Inclusion of Organic Chemistry in First Year High School ...



Inclusion of Organic Chemistry in First Year High School Chemistry

By Tom Horsley

The Pennington School 2002

Introduction

Motivating students to do their best work both in and out of the classroom is often a challenging task especially in a subject that students perceive as being difficult and unimportant to their existence. Chemistry is arguable one of the most difficult subjects to teach and to learn. Students resist the necessity to integrate creativity and visualization skills cultivated in art classes, the mathematics learned across the hall, grammar and sentence structure learned in English, the perspective and appreciation for time and past struggles fostered in history, and the organizational skills taught when learning a foreign language. While making chemistry more interesting and relevant to students may not make the subject any easier, it surely helps encourage them to give it their best effort. You do not have to look very hard to realize that high school students are truly very interested in chemistry whether they realize it or not. My students over the past year have done reports on a large number of chemicals they found interesting including, Ritalin, caffeine, ethanol, citric acid, anthracine, nicotine, nitrobenzene, ketamine hydrochloride, methamphetamine, anadrol, and many more[i]. The common denominator in each of these is that they are all organic substances.

Organic substances are usually left out of most high school chemistry courses because of the sophistication and complexity of organic chemistry. This does not need to be the case. There are a large number of organic compounds that can be used to explain and explore many of the concepts of chemistry. In addition, I found my students both capable of and interested in learning the basics of organic chemistry. By the end of the year it became apparent, from classroom observations and enrollment in AP Chemistry, that the students were more interested in chemistry than their peers from past years. Although the students continued to have difficulty in some areas of chemistry, their overall understanding seemed to benefit from the study of organic.

Teaching Environment

The Pennington School is a coed, college prep, independent, day/boarding school in Pennington NJ. There are three levels of chemistry, first year regular and honors and second year Advanced Placement. All the students attend college after graduation and about 20% of the students in the school have a diagnosed learning difference. While most of the students with learning differences elect the regular chemistry, a few are recommended for the honors course and some of these are able to move on to AP. The focus of my research was on the first year sophomore honors chemistry course. The classroom accommodates both the lecture/discussion and lab components of the course. It is equipped with a mounted computer projection system and “SmartBoard” and there is easy access to a computer lab. The available resources made visualization of the organic substances more efficient and interesting, however, they are not a necessity.

Methods Utilized

There were three main components of the study. First, organic substances were incorporate into traditional topics and included in lectures, discussions, labs, and assessments. Second, a three-week unit on organic chemistry was taught after chemical bonding. Third, after school workshops were lead by AP students to help support the first year honors students.

The incorporation of organic substances was a relatively easy task and included such things as plastics in discussions of chemical and physical properties, lauric acid and naphthalene in a phase changes lab, and ethanol in a density lab. Combustion of various hydrocarbons was used several times over the course of the year; when studying energy changes, types of chemical reactions, balanced equations, stoichiometric calculations and the gas laws. Once bonding and molecular structure was covered, the level of discussion of the organic substances became much more sophisticated and students were able to analyze and understand trends in properties such as vapor pressure, boiling point, and solubility.

The unit on organic chemistry introduced students to alkanes, alkenes, alkynes, isomers and simple nomenclature. It also included work with functional groups and some organic reactions including polymerization and etherification, which were also done as wet labs[ii]. The students did several paper labs[iii] on organic compounds that required drawing, naming, and constructing the compounds with molecular model kits.

The after school workshops covered a wide range of topics. AP students were provided with worksheets for the honors students that were intended to take 15 to 30 minute to complete. Using this time for students to work out some of their difficulties enabled the use of more class time to discuss applications of the concepts, which often included examples involving organic chemistry. There were approximately 20 workshops held over the course of the year, up to 2 per week.

Observations of Student Interest

Interest in lectures and class discussions seemed high and students were on task most of the time, although this is not unusual for the honors class. The students’ demonstrated great enthusiasm toward the organic unit, they particularly enjoyed working with the molecular model kits.[iv] Attendance at the workshops[v] seemed to depend on upcoming quizzes and tests but was much more effective than the standard “extra-help” time that our school builds into each day. Figure A below shows the enrolment in AP Chemistry in relation to the number of students who’s final average was in the “A” range over the last 5 years. Although the number of students who will elect AP Chemistry as a senior is undetermined, the increase for next year seems to indicate greater interest in chemistry.

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Evaluation of Student Understanding

Although scores on the organic unit test showed no statistical difference from the students overall test averages, they did do significantly better on the organic chemistry sections of the final exam.[vi] Figure B and C below present the final grade distribution and final exam distribution for the last 5 years. This data shows a decrease in the number of grades in the “C” and “D” range and an increase in the number of students in the “B” range with little change in the number of students receiving “A”s. This may indicate that the changes made this year had a greater affect on students of middle to lower abilities.

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Finally, figure D below shows student responses to a final exam question that is asked each year. This data clearly show that the students this year had a better understanding of the scale of different forms of matter on the microscopic level.

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Conclusion

Due to the small sample size and the fluctuation in student ability levels from year to year, it is difficult to conclusively state that the incorporation of organic chemistry into a first year honors high school chemistry course improved the overall level of understanding of the class. It can be concluded however that the students’ understanding and appreciation of the organic substances they encounter in their daily lives is greater than it would have been with out the study of organic chemistry. In addition, the increased interest level on the part of the students mirrored my own enthusiasm. I felt challenged to come up with new material to teach to my students and rewarded by their efforts to identify and learn about substances they ordinarily take for granted.

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[i]Horsley, Thomas. Student Work,

[ii] Heikkinen, Henry; Orna, Mary Virginia; and Schreck, James. “ChemSource ver 2.1,” ChemSource Inc., 1998, Vol 3 p. (ORGN) 5 – 10.

[iii] Horsley, Thomas. Organic Chemistry Teaching Materials,

[iv] Horsley, Thomas. Molecular Modeling,

[v] Horsley, Thomas. Workshops,

[vi] Horsley, Thomas. Sample Exam Responses,

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