Transient-Absorption Spectroscopy of Cis–Trans Isomerization of N,N-Dimethyl-4,4′-azodianiline with 3D-Printed Temperature-Controlled Sample Holder
Dmytro Kosenkov, James Shaw, Jennifer Zuczek, and Yana Kholod; J. Chem. Educ. 2016, 93, 1299–1304.
This article describes a laboratory unit demonstrating a project-based approach to teaching physical chemistry laboratory where upper-division undergraduates carry out a transient-absorption experiment investigating the kinetics of cis–trans isomerization of N,N-dimethyl-4,4′-azodianiline. Students modify a flash-photolysis spectrometer by adding a temperature-controlled sample holder. The sample holder design is open-source and can be reproduced with 3D printing technology. Students build the experimental setup, perform the transient spectroscopy experiment, and analyze the obtained kinetics data to estimate the activation energy, enthalpy, entropy, and Gibbs free energy of cis–trans isomerization of N,N-dimethyl-4,4′-azodianiline.
Vernier offers a flash-photolysis spectrometer with a Xe-flash pump and LED probe light sources, suitable for transient-spectroscopy experiments.
Development and Implementation of a Simple, Engaging Acid Rain Neutralization Experiment and Corresponding Animated Instructional Video for Introductory Chemistry Students
Danielle Rand, Craig J. Yennie, Patrick Lynch, Gregory Lowry, James Budarz, Wenlei Zhu, and Li-Qiong Wang; J. Chem. Educ. 2016, 93, 722–728.
The authors describe an acid rain neutralization laboratory experiment and its corresponding instructional video. This experiment provides a contextually relevant example to introduce beginner-level students with little or no acid-base chemistry background to the basic theories of solution chemistry. Using a Vernier Conductivity Probe in combination with LabQuest, students first measure the conductivities of various water samples. To simulate the neutralization reaction between acid rain and limestone as it occurs in nature, students pass a sulfuric acid solution through a column containing calcium carbonate and monitor the conductivity of the resulting solution. The supporting information provides an experimental procedure to distribute to students and includes an alternative method using a Vernier pH Sensor.
Evaluation of Existing and New Periodic Tables of the Elements for the Chemistry Education of Blind Students
Dennis Fantin, Marc Sutton, Lena J. Daumann, and Kael F. Fischer; J. Chem. Educ. 2016, 93, 1039–1048.
This article evaluates the accessibility of the Periodic Table of Elements that appear in Braille and audio-formatted chemistry textbooks, in some commercially available products, and mainstream chemistry websites. The Sci-Voice Talking LabQuest is a blind-accessible interface device primarily used as a data-acquisition system and built according to the principles of Universal Design. The Sci-Voice Talking LabQuest Periodic Table of Elements is navigated by using four raised arrow keys and a center key that can scroll through a list of 20 element properties.
Visualization of Kinetics: Stimulating Higher-Order Thinking via Visualization
Julie B. Ealy; J. Chem. Educ. 2016, 93, 394–396.
The author presents a modified kinetics experiment to include real-time visualization. This experiment engages students at higher-order cognitive skills through the analysis of their graphical results. Using a SpectroVis Plus Spectrophotometer, monitoring the disappearance of blue food coloring in a sodium hypochlorite solution introduces the simultaneous ability to immediately observe both the visual and graphical representation of the kinetics. The supporting information includes a student handout and instructor notes.
Simple Battery Experiment Reveals the Surprising Cost of Portable Electric Energy
John Lewis; The Physics Teacher. 2016, 54, 248.
In this article about battery testing, students use Logger Pro to graph current and voltage vs. time as the batteries are used, and they integrate to determine the energy stored. One interesting investigation compares the energy stored in AAA, AA, C, and D cells. Students are also asked to calculate the cost of the energy the cells provide and to compare cost to household AC electrical energy costs. Even though we sometimes think of batteries as inexpensive, the electricity from the batteries costs nearly $100/kWh or more, compared to the pennies we pay per kWh for AC electricity.
Evaluation of Rodent Spaceflight in the NASA Animal Enclosure Module for an Extended Operational Period (Up to 35 Days)
Eric L. Moyer, Paula M. Dumars, Gwo-Shing Sun, Kara J. Martin, David G. Heathcote, Richard D. Boyle, and Mike G. Skidmore; npj Microgravity. 2016, 1–7.
The National Aeronautics and Space Administration (NASA) conducted research on rodent habitats for shuttle flight missions using Vernier probeware. The project and findings are detailed in a recent article in npj Microgravity, a multidisciplinary research journal dedicated to publishing scientific advances in life sciences, physical sciences, and engineering fields that are facilitated by spaceflight and analogue platforms.
The article details how NASA developed a self-contained habitat, or an animal enclosure module (AEM), for rats and mice that provides the rodents with living space, food, water, ventilation, and lighting for space missions. Researchers collected data from the AEMs using Vernier Relative Humidity Sensors and Stainless Steel Temperature Probes with National Instruments LabVIEW™ software and SensorDAQ interfaces. Carbon dioxide and ammonia levels were also measured. Findings proved that with some modifications, the AEMs could be used on the International Space Station or other operational platforms to extend the space life science research use of the rodents.
Read the complete article at Nature.com