Have you ever wondered where the cloud comes from when dry ice is placed in water? If you think the answer is “atmospheric water vapor”, be sure to read this post because experimental evidence suggests that this explanation is wrong.
Solution to Chemical Mystery #6 is presented. Also, concepts related to the chemical can crush demo are briefly discussed.
For my students and me, the AP Chemistry exam does not mark the end of the school year. Once the AP exam is over, my students are exhausted but our class continues to meet for three more weeks. Each year we complete a qualitative analysis lab, but this year we finished earlier than I anticipated. For the first time all year, I have the luxury of time.
A few years ago, we launched a weather balloon during our summer science camp. The balloon reached an altitude of 30 km (100,000 ft)! Among other things, this project ended up being a great way to teach campers about the gas laws and how atmospheric pressure decreases with altitude.
Build a propane gun for your students! Construction is inexpensive, easy, and the effects are spectacular.
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.
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.
The nail bottle demonstration is one that many of us have conducted in our classes. To perform this demonstration, 2 – 3 mL of ethanol is placed into a plastic bottle that has two nails punctured into opposite sides of the bottle. After stoppering the bottle, a Tesla coil is touched to one of the nails. A spark jumps from one nail to the other, which initiates the combustion of vaporized ethanol inside the bottle. We recently filmed this reaction with our high speed video camera.
In this Activity, students explore buoyancy with helium-filled Mylar balloons. They use the ideal gas law to predict the mass of the balloon if it were empty, compare it to the actual mass of the empty balloon, and discuss experimental sources of error. This Activity demonstrates the ideal gas law and introduces students to the concept of buoyancy.