As our Gas Laws unit was coming to an end, it was time to create the test. As I thought of potential test questions that were both challenging and in alignment with the learning objectives we had previously identified for the unit, I was reminded of a multiple-choice question I had been shown in an old Modeling InstructionTM resource.
It is becoming increasingly important for citizens to understand various concepts related to climate change and global warming. This post describes several chemical concepts that are pertinent to these issues, in the hopes that teachers of science and chemistry can introduce the topic of climate change into their classrooms and everyday discussions.
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?
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?
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.
The August 2016 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: blue bottle reaction revisited; precollege professional development; chemical education research on intermolecular interactions and bonding; integrated courses; activities involving kinetics, enzymes, and gases; nanomaterial & polymer laboratories; organic synthesis; NMR teaching resources; book recommendations for summer reading.
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.
45 minutes or less
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.