demonstrations

Chemistry in a Bottle

Tom Kuntzleman | Fri, 05/05/2017 - 07:06

Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies. Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle. The plastic pieces display curious floating and sinking behavior when the bottle is shaken.

Demonstration: Reaction of Magnesium and Silver Nitrate

Kaleb Underwood | Tue, 05/02/2017 - 08:55

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I found a version of this demonstration online a couple of years ago. I admit, when I first tried it with my class it was mostly for a crowd pleaser to demonstrate the activity series of metals, but I then became very intrigued by the processes occurring. The original source only referenced the “single replacement reaction” between Mg_(s) and AgNO3_(aq). Therefore, when I saw a grayish product (silver) I was not surprised. However, I was surprised by the white flash and the production of a white product, which were reminiscent of the classic combustion of magnesium demonstration. This led to some research and my conclusions that follow. Read through to the end and you will find a video of the demo.

A replacement Maxwell-Boltzmann Distribution Simulation

Lowell Thomson | Fri, 04/21/2017 - 21:36

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A simulation for studying Maxwell-Boltzmann Distribution Curves, as the previous used online simulation was no longer working due to Java issues.

Investigations of Chemicals in Natural Food Coloring. Part 3: Sunflower

Tom Kuntzleman | Tue, 03/28/2017 - 08:39

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The chemistry of the Sunflower dye found in McCormick’s Color from Nature food dyes is explored in this post. This is the last in a three-part series in which several experiments and demonstrations that can be done with Color from Nature food dyes are described.

Investigations of Chemicals in Natural Food Coloring. Part 2: Berry

Tom Kuntzleman | Mon, 02/27/2017 - 13:42

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The chemistry of the Berry dye found in McCormick's Color From Nature food colors is explored. This is part two of a three-part series in which the chemistry of McCormick's Color From Nature food colors is presented.

Boiling Water, Heating Curves, and Can Crushes

Doug Ragan | Wed, 02/22/2017 - 23:51

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In an effort to better understand my high school students' knowledge of what is happening during phase changes, heating curve calculations, and the ever popular can crush demo, I run them through a series of activities. First, I ask my students "What Temperature Does Water Boil At?"

Chemical Investigations of McCormick's Color From Nature Food Colors. Part 1: Sky Blue

Tom Kuntzleman | Tue, 01/31/2017 - 09:15

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The chemistry of the Sky Blue dye found in McCormick's Color From Nature food colors is explored. This is part one of a three-part series in which the chemistry of McCormick's Color From Nature food colors is presented.

Hoffman Apparatus on the Go....

Chad Husting | Sun, 01/22/2017 - 08:01

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There are many places online to build a DIY Hoffman apparatus. The ACS offers an electrolysis of water lesson that includes a hand made Hoffman apparatus(link is external) as part of a unit on energy that I used as a resource.

Solution to Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice

Tom Kuntzleman | Mon, 01/16/2017 - 09:21

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The solution to Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice is presented. Why does liquid nitrogen launch the bucket so much higher than dry ice and water?

Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice

Tom Kuntzleman | Thu, 01/12/2017 - 07:20

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A 2L soda pop bottle is filled about one-third full with either liquid nitrogen or solid carbon dioxide (dry ice) and water. The bottle is sealed and a plastic bucket is placed on top. Do you think the liquid nitrogen or dry ice and water will make the bucket go higher? Can you explain the results using chemistry?