Is it possible to use materials found in high school chemistry labs to extract and subsequently detect cocaine on dollar bills? Let me know what you think after reading this blog post!
Like most chemistry teachers, one of the first things I go over in the beginning of the year is unit conversions. Students come into my class with all sorts of prior knowledge concerning unit conversions; some good, some bad and some downright ugly.
This exercise is intended as an ice-breaker for a first or second class meeting. It also serves as an introduction to physical & chemical properties and application of the macro/micro/symbolic representations of chemical phenomena. Finally, it also provides a framework to mention many of the topics to be covered in a general chem first semester course.
In Chemical Mystery #7, a can of Coca-Cola was observed to sink in one container of water and yet float in another! This trick made use of the fact that the density of water changes with temperature. See the video below.
Q: Does an unopened can of soda pop float or sink in water?
A: It depends!
See if you can figure out what is happening in this twist on the classic floating-and-sinking soda can experiment.
It's been a few days since my summer break began. I have had a few days to decompress, relax, and think about my next post. I have been planning to write about concept mapping since the end of our first semester. I first recognized the effects of concept mapping in the classroom when I read Shannon Bowen's blog post last December.
During our review since last week, resonance was labeled as one of the most tricky concepts (along with electron pushing in my opinion), despite lots of practice and instruction. My teaching sequence consists of defining and providing examples of conjugation (after learning about hybridization), delocalized electrons, and finally pushing electrons if conjugation exists. I remember from teaching at the college level that resonance was also a tricky topic for many undergraduates.
Solution to Chemical Mystery #6 is presented. Also, concepts related to the chemical can crush demo are briefly discussed.
Can you figure out how this experiment works?
I recently stumbled across a blog about the use of BCA (Before Change After) tables for stoichiometry written by Lowell Thomson. I was thrilled to discover ChemEd Xchange! I wanted to share my journey, spurred on by my s