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Thomas Kuntzleman

By on August 14, 2008 in Faculty Publications

Kuntzleman, Thomas S., David Sellers, and Rachel Hoffmeyer. “‘ Having a Ball with Chemistry’: More Things to Try.” Journal of Chemical Education 85, no. 11 (2008): 1478.

Abstract: A short outreach activity is described in which students test the rebound properties of superballs, racquetballs, “happy” balls and “sad balls” at many temperatures. After conducting the experiment, students use the test results to estimate the glass transition temperature of the elastic polymer that comprises each ball. The activity is used to segue into the classic demonstration of dipping a racquetball in liquid nitrogen and watching it shatter when thrown against a hard surface. In addition, students are encouraged to relate the results of the experiment to the importance of warming up muscles before exercise.

Thomas Kuntzleman

By on November 13, 2007 in Faculty Publications

Swanson, Matthew S., Deborah K. Sayers, and Thomas S. Kuntzleman. “Visualizing the Transition State: A Hands-on Approach to the Arrhenius Equation.” Journal of Chemical Education 84, no. 11 (2007): 1776.

Abstract: An exercise is presented in which the kinetics of the irreversible “reaction” of pennies in the heads-up state to pennies in the tails-up state is simulated by a hands-on, Monte Carlo approach. In addition, the exercise incorporates a second simulation in which the irreversible “reaction” of dice with a red face uppermost to a blue face uppermost is conducted. The transition states of the reactions are assumed to be a penny that is in the process of being flipped or a die in the process of being rolled, respectively. Data collected by students who perform these simulations show that both “reactions” follow first-order decay kinetics. Arrhenius plots from these data yield activation energies comparable to assigned values and pre-exponential factors close to what would be expected based on the probability of a “reactant” achieving the correct orientation for conversion into “product”. A comparison of the values obtained for the pre-exponential factors for the different simulations allows students to semi-quantitatively discuss the orientational requirement that is contained within this factor.

David Johnson

By on May 7, 2007 in Faculty Publications

Labban, Abdul, Roger Berg, Jian Zhou, David A. Johnson, and Edgar F. Westrum. “Heat capacities and derived thermodynamic properties of lithium, sodium, and potassium disilicates from T =(5 to 350)K in both vitreous and crystalline states.” Journal Of Chemical Thermodynamics 39, no. 7 (July 2007): 991-1000. doi: 10.1016/j.jct.2007.01.001

Abstract: Abstract: Cryogenic heat capacities determined by equilibrium adiabatic calorimetry from T =(6 to 350)K on Li, Na, and K disilicates in both crystalline and vitreous phases are adjusted to end member composition and the vitreous/crystal difference ascertained. The thermophysical properties of these and related phases are estimated, compared, and updated. The values at T =298.15K of {S ∘(T)− S ∘(0)}/R for stoichiometric compositions of alkali disilicate (M2O·2SiO2): vitreous, crystal: Li, 16.30, 14.65; Na, 20.67, 19.47; and K, 23.26, 23.00. Entropy differences confirm greater disorder in the vitreous compounds compared with the crystalline compounds. The entropy data also show that disorder increases with decreasing atomic mass of the alkali ion.

Bruce Baldwin

By on May 7, 2003 in Faculty Publications

Baldwin, Bruce W. “Manual Microscale Column Chromatography Pressurization Apparatus.” Journal Of Chemical Education 80, no. 10 (October 2003): 1182. doi:

Abstract: Pressurization of a Pasteur pipet for microscale chromatography is simplified by connecting a 20- or 30-mL syringe to the pipet using a length of Tygon tubing. This simple system allows the student to easily dry-pack a column using common chromatography packing materials. Results were uniformly good for introductory, organic, or upper-division research chemistry students.

Bruce Baldwin

By on November 13, 2002 in Faculty Publications

Wilhite, David M., and Bruce W. Baldwin. “Triboluminescent Crystals from the Microwave Oven.” Journal of Chemical Education 79, no. 11 (2002): 1344.

Abstract: Anthranilic acid was acetylated in a microwave oven (1,000 W) by irradiating for one minute at full power in a 100 mL beaker fitted with a glass funnel as condenser. After cooling, yellow fluorescing crystals were often obtained; but, if not, recrystallization from 10% water–methanol yielded cubes that fluoresced brightly under 360 nm light. Crushing the crystals between two watch glasses in a darkened room demonstrated the triboluminescent effect (i.e., the production of bright blue sparks when the crystals are fractured).