Did any of you guess what was going on in Chemical Mystery #4: The Case of the Misbehaving Balloon? In this experiment, several balloons were placed in liquid nitrogen. Most of these balloons shrunk tr
Although many students have been exposed to the concept of density before reaching my Chemistry class, I always start the year with this POGIL-like activity.
Approximately one hour including the debrief (I recommend holding a whole-class discussion for the summarizing questions that follow the What is density? activity and a selection of mathematical computation problems from the How can you calculate density? activity.)
One day during class I presented the disappearing rainbow demonstration and explained the chemistry behind it. After doing so, I had a student ask me if a particular bartending trick called “rainbow shots” was done in a manner similar to the way the disappearing rainbow demonstration is performed.
A paper square rubbed with graphite on one side is placed at the interface between two immiscible liquids, hexane and water.
A cast iron bomb is completely filled with ice water, then placed into a dry-ice/acetone slush and covered with a wooden box. When the water in the bomb freezes, the cast iron bomb explodes, breaking into several pieces, and destroying the box in which it was placed.
A normal ice cube is less dense than liquid water, but a deuterium oxide ice cube is more dense than liquid water.
An H2O ice cube is less dense than liquid water, but a D2O ice cube is more dense than liquid water.