Dean Campbell tries to use at least one demo for every class to illustrate concepts described in his chemistry courses. In this post, he includes short descriptions of the demonstrations and props he has used while teaching his collegiate General Chemistry II courses.
The reaction of hydrogen and oxygen gases to form water is well known to be an exothermic reaction. That reaction can occur by first absorbing the hydrogen into palladium metal, and then placing the resulting palladium hydride into contact with oxygen in the air. Infrared and visible light videos were recorded for this process involving palladium foil, and the Green Chemistry and safety aspects of these activities are considered.
The familiar soda fountains that can be produced by adding Mentos candies to plastic bottles of carbonated beverages can also be produced by adding objects to carbonated beverages in aluminum cans. A variety of simple methods for producing soda fountains from cans are described.
One of my goals for 2017 was to read more chemistry non-fiction. I accomplished that with three and a half books read. That doesn't seem like much, but given how busy I've been lately it was quite an accomplishment! I offer a brief review of my most recent book here, "The Alchemy of Air" by Thomas Hager.
I recently watched a video in which a chemist (who goes by the nickname “NurdRage”) activated a chemiluminescent reaction by vapor deposition. I wanted to try it out for myself! Unfortunately, oxalyl chloride is toxic, corrosive, and a lachrymator. Thus, the experiment conducted by NurdRage needs to be conducted in a hood, and it is not particularly amenable to simple presentations. I began to wonder how I could create this vapor activated chemiluminescence using simple materials.
In one of my last blog posts I wrote of how I sometimes enjoy ending a unit with a series of demonstrations and using them to elicit a dialog between the students and myself to check for understanding. It is always a fascinating experience to hear the misconceptions that many students have the day before the test.
The “Elephant Toothpaste” experiment is a very popular, albeit messy chemistry demonstration. To carry out this experiment, place a 250 mL graduated cylinder on something that you wouldn’t mind getting messy.
Happy New Year! Did you know that 2015 is the International Year of Light (IYL)? IYL is a “global initiative adopted by the United Nations to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in energy, education, agriculture, communications and health1”. IYL is sponsored by several organizations with interests in science and science education, including the European Physical Society, the Institute of Physics, the American Physical Society, and the American Institute of Physics. You can find several lesson plans, videos and other educational resources on the IYL website2.
In this Activity, students prepare cyanotype paper and use it to "photograph" different items using sunlight. This Activity demonstrates catalysis of chemical reactions by ultraviolet (UV) light using one of the earliest photographic processes, the cyanotype process. It is useful as an introduction to the damaging effects of UV radiation on living organisms and the role of sunscreens.
When acidic dichromate and iodide solutions are mixed, no immediate reaction takes place. Addition of iron(II) solution brings about rapid formation of brown triiodide.
