Ice Clouds 2.0
Tom Kuntzleman | Tue, 01/16/2024 - 15:12
What is some of the chemistry involved in the formation of ice clouds when boiling water is thrown into icy air?
Phases / Phase Transitions / Diagrams
Freezing Point Depression Near Body Temperature with Eicosane and Azobenzene
Dean Campbell | Tue, 11/02/2021 - 11:20
Addition of a small amount of azobenzene to eicosane can lower its melting point to where it can be melted by body heat. This can be used in demonstrations and classroom activities related to freezing point depression and phase diagrams.
Two Simple and Cheap Illustrations of Phase Equilibrium and Vapor Pressure
Kaleb Underwood | Sat, 08/04/2018 - 12:37
A favorite demonstration is to boil water by lowering the pressure in a bell jar using a vacuum pump. Unfortunately, purchasing a bell jar, vacuum plate, and vacuum pump can run upwards of $1,000 which poses a hardship for many teachers. Here are two simple and inexpensive demonstrations of phase equilibrium and vapor pressure.
Collection of and Experiments with Liquid Air
Tom Kuntzleman | Tue, 05/15/2018 - 20:18
Simple methods to prepare liquid air are described. In addition, ways to test the properties of liquid air and other liquefied gases are explored.
Solution to Chemical Mystery #11: Too Hot to Boil?
Tom Kuntzleman | Tue, 03/06/2018 - 09:26
The solution to Chemical Mystery #11, which involves the Leidenfrost Effect, is presented.
Chemical Mystery #11: Too hot to boil?!
Tom Kuntzleman | Fri, 03/02/2018 - 11:04
What happens if you place metal that is glowing orange-hot into some water? Watch this video and find out!
Temperature Experiments with the Scrub Daddy Sponge
Tom Kuntzleman | Wed, 02/21/2018 - 10:59
What happens if you cool a Scrub Daddy sponge in liquid nitrogen (or dry ice) and subsequently strike it with a hammer? Let's find out!
Solution to Chemical Mystery #10: Out of the Blue!
Tom Kuntzleman | Wed, 07/05/2017 - 09:30
In Chemical Mystery #10, plastic straws are observed to “magically” change color when waved in the air. Check out the explanation and the video.
Chemical Mystery #10: Out of the Blue!
Tom Kuntzleman | Fri, 06/30/2017 - 15:11
In this simple trick, colors are made to "magically" appear and disappear on a straw. This science experiment is very easy to do...if you know your chemistry!
Boiling Water, Heating Curves, and Can Crushes
Doug Ragan | Wed, 02/22/2017 - 23:51
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?"