Activity pubs.acs.org/jchemeduc
Fact or Fiction? General Chemistry Helps Students Determine the Legitimacy of Television Program Situations Mark A. Milanick* and Ruth L. Prewitt Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri 65211, United States S Supporting Information *
ABSTRACT: A large number of students in chemistry courses are thinking about pursuing careers in the health professions. We used a segment from the popular TV show, Bones, to illustrate how basic chemical concepts can help them solve complex physiological and medical problems. Many students have found the use of the Bones video clip engaging, and appreciated seeing the connection of chemistry to “real-world” situations. This presentation is intended to take chemistry out of the mundane classroom setting and present it in the context of a thrilling (albeit highly improbable) life-or-death scenario.
KEYWORDS: General Public, High School/Introductory Chemistry, First-Year Undergraduate/General, Biochemistry, Interdisciplinary/Multidisciplinary, Acids/Bases, Applications of Chemistry, Atmospheric Chemistry, Reactions n an episode of the TV series Bones entitled “Aliens in a Spaceship”, the characters Temperance Brennan and Jack Hodges are buried in their car by a kidnapper.1 If the ransom is paid before they run out of oxygen, the kidnapper will reveal the GPS coordinates of their location and they can be saved. How did the kidnapper (and Brennan and Hodges’s coworkers) calculate how long the oxygen would last? We used a video clip from this program as the initial hook for an hour-long presentation illustrating some of the ways chemistry can be used to solve this problem. This Journal has published several reports on the use of video clips and popular culture as hooks for engaging chemistry students recently. Clauss2 has summarized several examples, including an article by Milliard3 that features 10 television clips. Frey et al.4 have provided a number of movie clips that can be used as captivate students. Other methods include using medically relevant unit conversion in order to show the value of chemistry in reaching a diagnosis5 and the use of detective stories to interest students in chemistry.6 This article shows another example in which we use a video clip that includes a mystery of some medical relevance in order to capture the interest of undergraduate students enrolled in an introductory chemistry course.
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career in medicine or the health professions. Our goal was to give examples to students of the importance of chemistry in physiology; in part because chemical concepts make teaching of undergraduate, graduate, and medical physiology easier. We found that by starting with the clip of this Bones episode1 we immediately captured the students’ interest. They became engaged in solving this problem and realized that the calculations involved to solve this were not mere mathematics exercises, which helped them appreciate the value of the chemistry they were learning. We think this activity could be used with introductory students at the high school or college level, as well as the general public either as a way to motivate learning the chemistry or as a review of their general chemistry knowledge. The introductory undergraduate summer chemistry students commented that the medical relevance of the presentation helped them appreciate the usefulness of applying their chemistry knowledge. Other students were simply engaged by the story in the video.
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USING A VIDEO CLIP TO MOTIVATE LEARNING ABOUT MOLES, CONVERSIONS, AND REACTIONS We used a sequence from the 30:00 mark to 32:40 of the episode. This clip focuses primarily on Brennan and Hodges, as they are trapped in the car and running low on oxygen. Hodges gets the idea to create a carbon dioxide scrubber using a camera battery and some soda ash from Brennan’s preservation powder
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AUDIENCE FOR THIS ACTIVITIY In some of the undergraduate introductory summer chemistry courses at our institution, the instructor invites people from other disciplines to present a lab session on how chemistry has an impact on their profession. These students come from a variety of backgrounds, yet many are interested in pursuing a © XXXX American Chemical Society and Division of Chemical Education, Inc.
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dx.doi.org/10.1021/ed300155p | J. Chem. Educ. XXXX, XXX, XXX−XXX
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effects are irreversible and it is difficult to sustain life.9 At 8% CO2, the air in the car would be 12% O2. Would Brennan and Hodges survive at 12% O2 if most of the CO2 were removed? This is approximately equal to the percentage of oxygen at an altitude of 15,000 feet, a height at which people get sick if they are not acclimatized. We can infer that the carbon dioxide scrubbing will help Brennan and Hodges survive a bit longer as excess carbon dioxide will be lethal before the oxygen levels become too low to support life.
kit. How does this work? In the show, they claim that the carbon dioxide scrubber will also produce oxygenis this possible? In the rest of this paper, we will go over the questions we posed to the students and some of the approaches that can be used to answer them. Further discussion of applicable problemsolving approaches and potential prompting questions appears in the Supporting Information. Question 1. How Did the Kidnapper (and Brennan and Hodges’s Co-workers) Calculate How Long the Oxygen Will Last?
Question 5: In the Show, the Characters Claim That the Carbon Dioxide Scrubber Will Also Produce Oxygen. Is This Possible?
This question involves two separate components. The first one is: “How much oxygen is in the car?” For this, the students need to find or estimate the volume of the car and know that air is 20% oxygen. A convenient estimate is that a small car has an interior volume of 2240 L and contains approximately 20 mol of oxygen. The second component of this question is: “At what rate do humans use oxygen?” To answer this, the students can be prompted to “discover” that oxygen is used to react with glucose to produce ATP, which then serves as an energy source for cells. The average person uses the equivalent of 1/7 of a mole of glucose per hour, which means that about 1 mol of oxygen is consumed per hour.
This is a chance to make the students think and apply what they know. We asked them to think about why global warming is a problem or why some people worry about their carbon footprint. The problem is thought to be caused by too much carbon dioxide production. If we could convert carbon dioxide to oxygen (and some form of carbon), would that solve the problem? Plants do convert carbon dioxide to oxygen, but so far no chemist has devised any convenient, cost-effective method for doing that. In fact, the most common method of dealing with CO2 emissions from power plants is a type of chemical scrubbing.6
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SUMMARY Some students have commented that this enrichment session process helped them realize the value of understanding basic chemistry, and see that simple chemical concepts can help them solve complex physiological and medical problems. Many students have found the use of the Bones video clip engaging and appreciated seeing the connection of chemistry to “realworld” situations. This presentation is intended to take chemistry out of the mundane classroom setting and present it in the context of a thrilling (albeit highly improbable) life-ordeath scenario. We believe that this is an effective way of stimulating students’ interest in the subject.
Question 2. How Do the Soda Ash and Lithium Battery Work as Carbon Dioxide Scrubbers?
Lithium hydroxide as well as sodium hydroxide (as found in many drain cleaners) are used in carbon dioxide scrubbers because they react with carbon dioxide.7 Lithium batteries do not contain LiOH; this seems to be an error in the script. However, more traditional batteries known as nickel metal hydride batteries do contain LiOH. Students might be interested to learn that in space, LiOH is used rather than NaOH8 because it is lighter, and weight is an important consideration in getting things into space. An interesting laboratory experiment creating a carbon dioxide scrubber has been developed.7 Soda ash is sodium carbonate. A solution of sodium carbonate is alkaline. It is relatively easy to calculate that, for the same amount of total carbon in a closed system, the more alkaline the water phase, the more carbon is in the water, and therefore, the less in the air. Total carbon refers to CO2 in the air, CO2 dissolved in the water, carbonate, and bicarbonate ions in the water.
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ASSOCIATED CONTENT
S Supporting Information *
In-depth discussion of some of the questions in the paper; insights from our presentations. This material is available via the Internet at http://pubs.acs.org.
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AUTHOR INFORMATION
Corresponding Author
Question 3. How Much Soda Ash Would It Take?
*E-mail:
[email protected].
Students can begin solving this question by assuming that half of the 20 mol of oxygen have been consumed, and therefore, 10 mol of CO2 have been produced. This needs to be “scrubbed” with 5 mol of Na2CO3 or 10 mol of LiOH, which is equivalent to 1 kg of soda ash or 240 g of LiOH. One could take out a standard jar of these compounds and show how much space is required for this. In the show, the amount of powder is very small; it could be generously estimated as 24 g, which would remove 1 mol of CO2. This would be equivalent to gaining 1 h, if CO2 excess were the cause of death. This actually raises a question that is at the intersection of chemistry and physiology.
Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS We gratefully acknowledge the financial support for R.L.P. from the Mathematics in the Life Sciences program (NSF PRISM) at the University of Missouri. We also appreciate Jim Prewitt (no relation to R.L.P.) for allowing us to provide enrichment sections to several of his summer undergraduate chemistry classes at the University of Missouri.
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Question 4: In a Closed Container, Do You Die from the Lack of Oxygen or from Excess Carbon Dioxide?
Air is 20% oxygen and
