Tag Archives | Chemistry

Thomas S. Kuntzleman, Laura S. Davenport, Victoria Cothran, Jacob T. Kuntzleman, and Dean J. Campbell. “New Demonstrations and New Insights on the Mechanism of the Candy-Cola Soda Geyser.” Journal of Chemical Education, 94 no. 5, (February 23, 2017) 569-576

Abstract: When carbonated beverages (which are supersaturated solutions of aqueous carbon dioxide) are confined within a narrow-necked container, events which rapidly release the gas from solution produce a fountain out of the beverage. One well-known variant of this experiment is the addition of Mentos candies to a bottle of Diet Coke. Previous reports have shown that the presence of aspartame and benzoate in carbonated beverages enhance the fountaining effect. These additives are thought to enhance fountaining by lowering the surface tension of the beverage, but the details of this process are not completely understood. This paper explores the relationship between geyser height and the type of carbonated beverage. It is shown herein that several other compounds commonly found in commercial carbonated drinks such as sucrose, glucose, citric acid, and components of natural flavors also enhance geyser heights. By examining how these additives affect bubbling and foaming behavior in seltzer water, it is postulated that solutes which inhibit bubble coalescence contribute to higher fountains.

Sims, Trevor P. T., and Thomas S. Kuntzleman. “Kinetic Explorations of the Candy-Cola Soda Geyser.” Journal Of Chemical Education 93, no. 10 (October 11, 2016): 1809-1813.

Abstract: Protocols for examining the kinetics of CO2 escape from solution during the popular Diet Coke and Mentos experiment have been explored. The methods developed allow teachers to demonstrate and students to explore various physicochemical processes involved when Mentos candies are placed in Diet Coke. For example, a pH meter can be used to observe a slight decrease in acidity as dissolved CO2 escapes the soda. Furthermore, a balance or CO2 sensor can be used to directly measure CO2 escape. Arrhenius analysis of degassing rates determined using these latter methods yielded an activation energy of 25 kJ mol-1 for the conversion of CO2(aq) to CO2(g). The materials required for the experiments are easy to acquire and set up; therefore these investigations are amenable for use in high school and undergraduate chemistry classrooms and laboratories.

Hall, Johnathon M., John R. Amend, and Thomas S. Kuntzleman. “Experiments to illustrate the chemistry and bouncing ability of fresh and spent zinc-manganese oxide alkaline batteries.” Journal Of Chemical Education no. 4 (2016): 676-680.

Abstract:Why do dead batteries bounce considerably higher than fresh batteries? This phenomenon has a chemical explanation that can be used to teach students about the chemistry of alkaline Zn/MnO2 cells. Batteries discharged to various extents can be tested for bounciness and conversion of Zn to ZnO. These measurements allow students to connect the chemistry that powers these batteries with the increased bouncing effect. The experiments can be presented as a teacher-led demonstration or hands-on laboratory for students.

Kuntzleman, Thomas S., and Erik C. Jacobson. “Teaching Beer’s Law and Absorption Spectrophotometry with a Smart Phone: A Substantially Simplified Protocol.” Journal of Chemical Education, January 29, 2016. doi:10.1021/acs.jchemed.5b00844.

Abstract: A very simple protocol for teaching Beer’s Law and absorption spectrophotometry using a smart phone is described. Materials commonly found in high school chemistry laboratories or even around the house may be used. Data collection and analysis is quick and easy. Despite the simple nature of the experiment, excellent results can be achieved.

Hall, Johnathon M., John R. Amend, and Thomas S. Kuntzleman. “Experiments To Illustrate the Chemistry and Bouncing Ability of Fresh and Spent Zinc–Manganese Oxide Alkaline Batteries.” Journal of Chemical Education (published online January 2016). doi: 10.1021/acs.jchemed.5b00796

Abstract: Why do dead batteries bounce considerably higher than fresh batteries? This phenomenon has a chemical explanation that can be used to teach students about the chemistry of alkaline Zn/MnO2 cells. Batteries discharged to various extents can be tested for bounciness and conversion of Zn to ZnO. These measurements allow students to connect the chemistry that powers these batteries with the increased bouncing effect. The experiments can be presented as a teacher-led demonstration or hands-on laboratory for students.

Kuntzleman, Thomas S.  “National Chemistry Week: A Platform for Scholarship“. Journal of Chemical Education 92, no. 10 (October 2015): 1585-1588. doi: 10.1021/acs.jchemed.5b00660

Abstract: National Chemistry Week (NCW) is an annual centerpiece for chemistry outreach orchestrated by the American Chemical Society. During this week, chemical educators promote chemistry through public lectures, demonstrations, and hands-on experiments. These exhibits inspire and motivate students, young and old, to study and appreciate chemistry more deeply. Chemical educators also benefit through participation in NCW, because doing so has great potential to initiate and advance scholarly efforts. How outreach efforts such as those associated with NCW can stimulate and support scholarship in chemistry is described.

Kuntzleman, Thomas S. “The dynamic density bottle: a make-and-take, guided inquiry activity on density.” Journal Of Chemical Education no. 9 (2015): 1503.

Abstract: An activity is described wherein students observe dynamic floating and sinking behavior of plastic pieces in various liquids. The liquids and solids are all contained within a plastic bottle; the entire assembly is called a “density bottle”. After completing a series of experiments that guides students to think about the relative densities of both the liquids and solids in the bottle, students are able to explain the curious floating and sinking phenomena. As a part of the activity, students construct their own bottles and are encouraged to describe to others how the density bottle works. These bottles can be constructed using inexpensive and easily obtained materials. The level of inquiry involved in the activity can be tailored to meet the particular interests and needs of students. Modifications to the density bottle, including an engaging one that uses LEGO pieces, are discussed.

Kuntzleman, Thomas S., Nathan Ford, Jin-Hwan No, and Mark E. Ott. “A Molecular Explanation of How the Fog Is Produced when Dry Ice Is Placed in Water.” Journal Of Chemical Education 92, no. 4 (April 2015): 643-648. doi:10.1021/ed400754n

Abstract: Everyone enjoys seeing the cloudy white fog generated when solid carbon dioxide (dry ice) is placed in water. Have you ever wondered what physical and chemical processes occur to produce this fog? When asked this question, many chemical educators suggest that the fog is produced when atmospheric water vapor condenses on cold carbon dioxide gas that sublimes through the water. But this explanation is incorrect, as shown by Luck and co-workers in an article previously published in J. Chem. Educ. Herein, we extend this previous work by presenting some simple experiments and explanations that provide a model for how the fog forms when dry ice is placed in water. Many of these experiments can be carried out using materials found at the pharmacy, grocery store, or hardware store. The explanations involved draw from many concepts taught in general chemistry such as vapor pressure and Le Châtelier’s principle.

Kuntzleman, Thomas S., Dakota J. Mork, Levi D. Norris, and Christopher D. Maniére-Spencer. “Creating and Experimenting with Fire Gel, an Inexpensive and Readily Prepared Insulating Material.” Journal of Chemical Education 90, no. 7 (July 2013): 947–949. doi:10.1021/ed3006506.

Abstract: A method is described to make Fire Gel, an insulating material that consists of water and a superabsorbent polymer. Fire Gel can be used to demonstrate how stunt persons protect themselves from the flame of a fire. A comparison of this Fire Gel demonstration with previously reported flame protection demonstrations allows for instructive discussion. Fire Gel is a useful, easily produced, and inexpensive alternative to the gel described in JCE Classroom Activity #107.