Chemical Patterns in Autoxidations Catalyzed by Redox Dyes

Abstract

We present simple and effective experiments to produce intricate chemical patterns from common chemicals in a classroom setting. Students selected an independent variable of their interest, designed their experiment, and investigated its effect on chemical patterns in a four-hour activity. Photographs and videos were taken, while the identity and the concentration of chemicals in the reaction mixture, the concentration of oxygen gas above the solution, the depth of the solution, the shape and the total area of container’s cross section, and the temperature were varied. Students discussed their results and presented their investigation to the class. Our experiments enable students to conduct inquiries with open-ended discussion and also open possibilities for a chemical art competition.

Intuitive Small-Scale Electrochemistry on 24-Well Plate and 3D-Printed Cover Yielding Accurate Results

“…The 3D-printed scaffold helps provide convenient and reusable support to electrodes (metal strips or plastic droppers) on the 24-well plate. In the past, we used plasticine to provide such support, but we found that our “3D-printed laboratory equipment” − is cleaner and more convenient for our students. While the use of a 24-well plate significantly reduces the amount of electrolyte solution for each electrode to well below 2 mL, the open-circuit cell potentials remain close to the literature value, as per Table .…”

“…In line with the development of educational experiments, the availability of affordable and reusable plastic equipment , and 3D-printing technology − has made this small-scale experiment possible. Likewise, thanks to cheap multimeters and electronic devices, a minute amount of electricity from galvanic cells described here can be measured and shown to easily produce light and sound.…”

ACAD-Feedback: Online Framework for Assignment, Collection, Analysis, and Distribution of Self, Peer, Instructor, and Group Feedback

“…This is applicable when a group submits only one report for an experiment rather than separate individual reports. In this regard, we piloted the new scheme in the introductory chemistry laboratory class (Figure ; folder 2 in the Supporting Information) by asking students to declare their contribution manually in their lab reports based on standard statements in the CRediT system for a special experiment in a term. During the emergency online delivery of lab class, the group report submission was extended to more experiments to help increase the interaction of group members.…”

The Blue Bottle Experiment Revisited: How Much Oxygen?

“…The blue bottle experiment and its variants are often discussed in this Journal − and elsewhere. − Though simple, popular, and well-studied, a number of misconceptions and oversights have been corrected: for example, the oxygen consumption is not reversible; , the redox dye is not an oxygen carrier; the main product is not gluconate; ,,− some dyes do not work as claimed; − ,, and benzoin is not a catalyst. , …”