“So You Think You Can Demo” is a fun and educational contest sponsored by ChemEd committee members to allow chemical educators to have a platform to share their best hands-on science demonstrations. We encourage all ChemEd 2015 attendees to submit a video showing off your most creative, informative and interesting chemistry demo. The deadline for submission of a demo video is April 30th.
The juice from an orange peel causes a balloon to pop. When I first saw this effect I immediately thought to myself, “what is the chemistry involved in this experiment?” After quickly searching the web, I found several claims that a compound in orange peels called limonene (Figure 1) is responsible for this effect. Limonene is a hydrocarbon, which means that molecules of limonene are composed of only carbon and hydrogen atoms. Limonene is responsible for the wonderful smell of oranges, and it is a liquid at room temperature.
Just the other day within my IB Chemistry HL classes, we were discussing the color of transition metal complex ions in solution. It's a bit imperfect, because they are not yet dissolved, but I set up a number of metal chloride salts in order to help students see the pattern. They are arranged according to the position of the metal in the periodic table. It ends up being quite obvious to the students that the only metal salts with color are in the d-block. I'm now in the process of ordering more chloride salts so I can complete the pattern even more the next time I teach this topic.
Conducting experiments with liquid nitrogen experiments is a sure-fire way to energize many chemistry lessons. Unfortunately, getting access to liquid nitrogen can be a bit difficult. I happen to purchase liquid nitrogen from Airgas; you might be able to find a branch near you here.
The “bucket launch” is a fantastic experiment you can do if you have access to liquid nitrogen. Depending upon conditions, we have observed the bucket to launch anywhere from 80 to 160 feet high. See the video.
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.
Cellulose nitrate (also known as nitrocellulose or guncotton) is a very flammable substance that is formed by reacting cellulose (also known as dietary fiber) with a mixture of concentrated nitric and sulfuric acids:
Engaging and Sustaining Students' Interest in Chemistry
The November 2014 issue of the Journal of Chemical Education is available online to subscribers at http://pubs.acs.org/toc/jceda8/91/11. The November issue content includes content on water chemistry, diversity and women in science, professional development, teaching with technology, electrochemistry, and more.
Congratulations to Grazyna Zreda who solved the Chemical Mystery of the Mentos candies! To conduct this trick, two white Mentos candies are placed in separate beakers that both contain universal indicator. One of the Mentos candies turns the indicator slightly green, indicating the presence of base.