In the Classroom
Chemistry in the Real World Martin B. Jones* Department of Chemistry, Adams State College, Alamosa, CO 81102;
[email protected] Christina R. Miller* Department of Chemistry, University of Northern Iowa, Cedar Falls, IA 50614;
[email protected] Numerous authors have addressed the subject of motivating students and maintaining their interest in introductory and general chemistry classes. Various tools and techniques have been employed: playing/solving chemistry-oriented games and puzzles (1, 2); discussing current chemistry events as gleaned from news media (3); exploring the chemistry involved in popular books (4–6 ), movies (5, 7), and television shows (8); having students write chemical fantasy essays (9), brief reports on relevant chemicals (10), essays involving chemistryrelated mysteries (11), or even chemical limericks (12); conducting debates (13) or trials (14) in class; stopping class in mid-lecture for assessment, feedback, or news breaks (15); having students participate in small-group activities (16 ); and incorporation of current research topics into the lecture (17 ). Some schools have addressed this matter by developing specific courses with an “issues” orientation (e.g., business, art, or environment) (18 ) or for “citizens” (19). Another approach is to use real-world examples in the classroom to illustrate the relevance of chemistry to students’ everyday lives. This technique was advocated in a symposium at the 7th Biennial Conference on Chemical Education at Oklahoma State University in 1982 (20). Diverse methods of introducing real-world examples have been reported (21–26 ). In one class, a suggestion box was made available at each lecture period so students could ask questions about real-world applications of the chemistry covered in the class (22). The instructor addressed each question in the first few minutes of the following lecture period. In another class, introductory chemistry students were asked to bring one written question concerning chemistry to a regular lecture class at mid-term (23). During that period, the instructor and invited guests (other professors and graduate students) answered 20 randomly selected questions. Students have been required to write a letter to a fictitious relative in which they answer a real-world chemistry question posed by the instructor (25). The letter was to be concise, clear, and readily understood by a nonchemist. The stated positive impact of incorporating real-world examples encouraged us to develop our own method of in-
cluding real-world chemistry in introductory courses, which we have termed “Chemistry in the Real World” (27 ). Description The value of real-world examples is not lost on textbook authors—most introductory and general chemistry texts feature vignettes that stress the relevance of chemistry to the world around us. However, unless the instructor makes a concerted effort to discuss those vignettes, from our experience, most students will not read those sections of the text. “Chemistry in the Real World” is a short (10–20-minute) discussion segment of the lecture portion of introductory chemistry. This segment occurs weekly, typically on Fridays, and focuses on a particular chemical or process that has practical applications or implications. Whenever possible, the topic is tied to course material that is currently being covered. If possible and appropriate, demonstrations are performed or samples are distributed to further illustrate the subject matter. Food samples seem to be particularly well received. Table 1 gives “Chemistry in the Real World” topics we have used for the two-semester sequence of Introductory Chemistry (general, organic, and biological chemistry) and for a one-semester general education chemistry course, Principles of Chemistry. Students seem to equate importance of material covered in a course with examination questions (“Is this going to be on the test?”), so we inform them that they will be tested on these “Chemistry in the Real World” discussions. Table 2 contains some sample examination questions for a few of these topics. Student Response Students have been quite receptive to the “Chemistry in the Real World” discussions. During the first two years, student feedback was largely anecdotal and consisted of comments made to the instructors and on evaluation forms (“I like the chem. in the real world”, “I enjoy the chem. in the
Table 2. Sample Examination Questions
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Topic
Sample Question
Ethanol
Why do "mixed drinks" stay mixed?
Lead–acid batteries
The electrical energy produced in a lead–acid battery comes from _____.
Fever
Briefly explain why a fever of over 104° is dangerous.
Acidulants
Name a typical acidulant used in foods and briefly explain why it can serve as a preservative.
Radiation
Name two ways Bruce Banner could have avoided radiation from the "gamma bomb".
Petroleum
Which of the following statements is true about the fractionation of petroleum?
Triclosan
What functional groups are primarily responsible for the antibacterial action of triclosan?
Steroids
Which of the following structures is testosterone?
Journal of Chemical Education • Vol. 78 No. 4 April 2001 • JChemEd.chem.wisc.edu
Evaporation, boiling, boiling points
Metallic bonding, transition metals and different oxidation states, magnetism Redox reactions, electrochemistry
Gas laws, specifically Boyle's law
Solutions, colligative properties
Reaction rates
Acid–base chemistry
Acid–base chemistry
Energy production, combustion
Effects of ionizing radiation and nuclear reactions
Definitions of organic chemistry
Hydrocarbons
Topical anesthesia
Iron
Lead-acid batteries
Breathing and Boyle's law
Aqueous salt solution
Fever
Acidifiers/acidulants
Acid precipitation
Greenhouse effect
Fantasy nuclear chemistry
Vital force theory
Petroleum
JChemEd.chem.wisc.edu • Vol. 78 No. 4 April 2001 • Journal of Chemical Education
Organic halides, aromatics, ethers, phenols
Carboxylic acids
Derivatives of carboxylic acids
Introduction to biomolecules
Carbohydrates, catabolism
Carbohydrates
Amino acids/peptides, cysteine oxidation–reduction
Triclosan
Retinoic acid
Polyesters
Nutrition
Glucose and diabetes mellitus
Blood groups
Glutathione
Enzymes and enzyme inhibition
Cycloalkanes, aromatics, lipids, functional groups
Steroid hormones
Penicillin
Aromatics
Aromatic compounds
Hydrogenation of vegetable oils Reactions of alkenes
Ethanol
Covalent bonding, polarity, redox reactions, Lewis structures, molecular and electron-pair geometries, enzymes Covalent bonding, polarity, Lewis structures
Hydrogen peroxide
Fireworks
Sugar
Composition of matter (elements vs compounds vs mixtures), ionic bonding, polarity, nomenclature, solubility Composition of matter, covalent bonding, polarity, solubility Metal ions, line spectra, electron distribution
Salt
Antibiotics and mechanism of action, antibiotic resistance
General protective agent in cells
ABO blood group system
Excess glucose in urine may indicate diabetes
PETE used for clothing, soda bottles, synthetic body parts; Lactomer used for surgical staples Importance of diet for good health
FDA-approved acne treatment, supposed wrinkle-remover
The Incredible Hulk, Spider Man, Godzilla (all created from encounters with ionizing radiation) Evolution of organic material from abiotic sources, Urey and Miller's experiments Gasoline and oil for automobiles, asphalt for roads, feedstocks for chemical industry Conversion of vegetable oils to margarines, saturated fats vs unsaturated oils Some essential oils, flavorings, mothballs, feedstocks for chemical industry, potentially carcinogenic PAHs from combustion Necessary for normal metabolic function as well as sexual characteristics and determination of sex Common antibacterial agent in deodorants
Environmental issue of global warming
Environmental issue of acid rain
Sore throat remedy, osmosis, adding salt to ice to make ice cream, adding salt to water to cook pasta or rice Fever increases the temperature of the body to kill bacteria, but increases the rate of reactions in the body Food additives for tart taste, preservatives, may be antioxidants
Artificial respiration by respirator
Important construction material, ionic forms needed for normal biological functions, commonly added to foods Automobile batteries
Ethyl chloride as topical anesthetic for sports injuries
Dilute solution is antiseptic and bleach, concentrated solution used in rocket propulsion; by-product of metabolic processes, substrate for catalase Alcoholic beverages, gasohol, antiseptic
Common spice, salt mines, salt caverns for storage of waste materials, production of chlorine and sodium from salt, pottery glaze Common sweetener, different sources and agricultural importance Fireworks, flares
Relevance to Students' World
Sample: penicillin tablet
None
None
Samples/demos: glucose test strips, glucose monitors
Samples: leisure suit (some old fogies may still have these), PETE soda bottles Samples: different types of foods (not candy)
Sample: Retin A cream
Samples: common deodorants
Oil of: clove (eugenol), wintergreen (methyl salicylate), bitter almond (benzaldehyde), cinnamon (cinnamaldehyde); vanilla beans (vanillin); foods containing one of these; naphthalene None
Samples: vegetable oils and margarines
Samples: motor oil
Demo: cartoon of how Bruce Banner is made (reversibly!) into the Incredible Hulk None
Demo: change in universal indicator color when SO2 is dissolved in water Demo: combust organic substances (paper, candle, methane)
Demo: difference in boiling point between pure water and aqueous salt solution Demo: iodine clock reaction in ice bath and hot water to show effect of temperature on reaction rate Samples: sour candy (malic or citric acid), vitamin C tablets
Demo: respiration mask with hand pump
Sample: automobile battery
Demo: presence of metallic iron in iron-enriched cereals
Demo/define "proof" of alcoholic beverages: burn paper money soaked in 50% ethanol (aq) Sample: spray can of ethyl chloride
Demo: catalytic decomposition of H2 O2 (using either KI or bloody meat such as liver, a good source of catalase)
Samples: refined and unrefined sugar, sweet food products (e.g., candy) Demo: typical flame tests for Sr, Cu, Na, etc.
Samples: halite, rock salt, table salt, sea salt, food products containing salt (i. e., salty snacks)
Samples/Demonstrations
Table 1. Chemistry in the Real World Topics for Introductory Chemistry Courses
Possible Course Material Tie-In(s)
Topic
In the Classroom
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In the Classroom Table 3. Sur vey Results Av Rating ± SD a 1st semester Intro. to Chem. (n = 29) b
Statement
2nd semester Intro. One-semester to Org. & Biochem. Principles of Chem. (n = 19) c (n = 36) c
I enjoy the Chemistry in the Real World segments in class.
4.79 ± 0.41
4.47 ± 0.61
4.08 ± 0.55
I feel that Chemistry in the Real World enhances my understanding of the topics covered in lecture.
4.31 ± 0.60
4.32 ± 0.67
3.94 ± 0.67
I think that Chemistry in the Real World has helped my performance in this class.
4.07 ± 0.70
3.63 ± 0.68
3.14 ± 0.79
I would like to see more Chemistry in the Real World presented in class.
4.45 ± 0.78
3.74 ± 0.81
3.80 ± 0.91
I believe that Chemistry in the Real World takes time away from class activities.
1.38 ± 0.73
1.47 ± 0.61
1.94 ± 0.79
a Ratings
were on a scale of 1 (strongly disagree) to 5 (strongly agree). b Course taught at Adams State College. c Course taught at University of Northern Iowa.
real world segments”). In the fall of 1999, we gathered more data on student opinions by asking students to complete an anonymous survey. This instrument consisted of five statements, to which the student could circle her or his level of agreement. Space was left for comments after each statement and for general comments at the end of the survey. The statements and the average rating (± SD) for each statement are given in Table 3 for the three courses surveyed. Overall, comments from the surveys were positive, indicating student satisfaction with the segments. The following are typical. I think it’s cool to find out how chemistry is involved so much in our lives. It makes the science more real and on a more personal level. I like chemistry in the real world because it applies what we are learning to real situations. I think it is easier to learn Chemistry using real world applications. Chemistry in the real world is fun and it lets you know about products that I use so it’s very helpful and educational. Chemistry in the real world does take time away from class but it is a nice break and is very interesting. I think that it teaches new things and it helps my understanding because of the demonstrations that are done. I wish every class did CITRW. I really enjoyed Chemistry in the Real World. In so many classes I find myself thinking, ‘when will I ever use this stuff?’ It’s nice to see chemistry apply to my everyday life and not just be an over-my-head, way-out-there concept. Because I am not a chem. major it helps me to relate this class to the world and what I might be doing in the future. It is an incentive to come to class on Fridays.
Some students stated that the discussions did not aid their understanding. I think it’s nice to add to lecture for purposes of application, but I don’t really think it helps in the understanding of concepts. Overall I enjoyed Chemistry in the Real World, but I don’t think that it affected my performance in the class. Sometimes Chemistry in the Real World was good, other times I would have liked to have had more time to go over difficult topics.
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Concluding Remarks Our goal for instituting the “Chemistry in the Real World” discussions was primarily to promote interest in and awareness of the role of chemistry in the world around us. From the comments students have made, that goal has been achieved. Students from the first class to participate in these discussions (Introductory Chemistry at Adams State College, fall 1997) still comment that they remember some Chemistry in the Real World segments. Current students have confided to us that they wished other classes in the sciences had similar “Real World” components. The instructor’s investment of time in preparing discussion material is worthwhile, as indicated by the interest shown and questions asked by students during the discussion. For example, the segment on lead–acid batteries invariably leads to questions concerning other types of batteries, which permits further discussion on oxidation– reduction reactions and electrochemistry. Background information and material for these discussions is readily available from textbooks (28), the Merck Index (29), this Journal (30), and other sources. Our approach differs from those cited earlier (21–26 ) in three significant ways. First, there is a regular time set aside for the real-world segments and we can use as much time as necessary to adequately cover and answer students’ questions about the topic. Second, the topics are chosen by the instructor, rather than by the students. This ensures that the topic is relevant to the lecture material. Third, students are tested on the real-world topics. This suggests to them that the instructor considers the application of chemistry to the real world to be of comparable importance to the chemistry principles given in the textbook. Incorporation of these segments decreases the amount of typical classroom time one day per week. However, since the discussions are focused on a practical example of chemistry currently being covered in the class, opportunities for review of concepts, reactions, even stoichiometry, are present. We have not had problems covering the necessary lecture material in the reduced time available. Our normal lectures are not devoid of practical examples or demonstrations just because we have set aside specific time for Chemistry in the Real World discussions. We try to incorporate the utility of chemistry whenever possible. Designating this time, however, assures that students will see the practical side of chemistry at least once a week. All in all,
Journal of Chemical Education • Vol. 78 No. 4 April 2001 • JChemEd.chem.wisc.edu
In the Classroom
this pedagogical addition has been enjoyable and educational for both the students and the instructors, and we plan to continue these segments. Literature Cited 1. Russell, J. V. J. Chem. Educ. 1999, 76, 481-484; this reference contains an annotated bibliography of many published and commercial games. 2. Subramaniam, R.; Goh, N. K.; Chia, L. S. J. Chem. Educ. 1999, 76, 484–488. Granath, P. L.; Russell, J. V. J. Chem. Educ. 1999, 76, 485–486. Russell, J. V. J. Chem. Educ. 1999, 76, 487–488. Deavor, J. P. J. Chem. Educ. 1996, 73, 430. Tejada, S.; Palacios, J. J. Chem. Educ. 1995, 72, 1115–1116. Most, C. Jr. J. Chem. Educ. 1993, 70, 1039–1040. Scarpetti, D. J. Chem. Educ. 1991, 68, 1027–1028. DeMeo, S. J. Chem. Educ. 1991, 68, 114–115. Helser, T. L. J. Chem. Educ. 1989, 66, 980. Stenz, J. C. J. Chem. Educ. 1988, 65, 791–792. Evans, M. H. J. Chem. Educ. 1985, 62, 1103. Walker, N. J. Chem. Educ. 1982, 59, 1026. 3. Myers, R. S. J. Chem. Educ. 1991, 68, 769–770. Fahrenholtz, S. R. J. Chem. Educ. 1989, 66, 217. Greenberg, F. G. J. Chem. Educ. 1985, 62, 227. DeLorenzo, R. J. Chem. Educ. 1982, 59, 531– 532. Mammano, N. J. J. Chem. Educ. 1980, 57, 286–287. Kolb, K. E.; Taylor, M. A. J. Chem. Educ. 1980, 57, 20–21. 4. Southward, R. E.; Hollis, W. G. Jr.; Thompson, D. W. J. Chem. Educ. 1992, 69, 536–537. 5. Last, A. M. J. Chem. Educ. 1992, 69, 206–208. 6. Hart, H. J. Chem. Educ. 1975, 52, 444. 7. Goll, J. G.; Woods, B. J. J. Chem. Educ. 1999, 76, 506–508. Hollis, W. G. Jr. J. Chem. Educ. 1996, 73, 61–62. 8. Hudson, R. L. J. Chem. Educ. 1987, 64, 1039–1040. 9. VanOrden, N. J. Chem. Educ. 1990, 67, 1052. 10. Bunyan, E. L. S. J. Chem. Educ. 1986, 63, 858. 11. DeLorenzo, R. J. Chem. Educ. 1999, 76, 503. DeLorenzo, R. J. Chem. Educ. 1997, 74, 1042. 12. Williams, F. D. J. Chem. Educ. 1995, 72, 1123–1124. 13. Singh, B. R. J. Chem. Educ. 1995, 72, 432–434. Streitberger, H. E. J. Chem. Educ. 1988, 65, 60–61. 14. Jones, M. A. J. Chem. Educ. 1997, 74, 537. 15. Olmsted, J. A. III. J. Chem. Educ. 1999, 76, 525–527. 16. Barraza-Ortega, Q. G. J. Chem. Educ. 1994, 71, 572. Holme, T. A. J. Chem. Educ. 1992, 69, 974–977. Steiner, R. P. J. Chem. Educ. 1980, 57, 433–434. 17. Holme, T. A. J. Chem. Educ. 1994, 71, 919–921. 18. Adams, D. L. J. Chem. Educ. 1999, 76, 1088–1091. Farrar, J. M.; Eisenberg, R.; Kampmeier, J. A. J. Chem. Educ. 1993, 70, 847.
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