thermochemistry

Gibbs Free Energy Analogy

A common topic in chemistry discussion groups and forums is about the use of the terms “spontaneous reaction” versus “thermodynamic favorability”. This is a new activity for chemistry students who struggle with the correlation between changes in enthalpy, temperature, entropy, and the Gibbs free energy of a system; which relies on an analogy that most students will be familiar with.

Boltzmann Bucks—Helping Students Conceptualize Entropy

If you are looking to go beyond using traditional, arguably misleading, definitions of entropy involving “disorder” and “messy bedroom” analogies, the Boltzmann Bucks game fits the bill. The game, pulled from a Journal of Chemical Education article, provides a wonderful opportunity for students to more accurately conceptualize entropy.

Chemical Thinking Interactives

As part of a two-week Chemistry Modeling Workshop™ in Houston, TX, I had the opportunity to read the by Vicente Talanquer of the University of Arizona. I researched Dr. Talanquer and discovered he created a collection of simulations called Chemical Thinking Interactives (CTI). These digital tools illustrate many chemistry topics with a focus on the particulate nature of matter.

Demonstration: Reaction of Magnesium and Silver Nitrate

I found a version of this demonstration online a couple of years ago. I admit, when I first tried it with my class it was mostly for a crowd pleaser to demonstrate the activity series of metals, but I then became very intrigued by the processes occurring. The original source only referenced the “single replacement reaction” between Mg(s) and AgNO3(aq). Therefore, when I saw a grayish product (silver) I was not surprised. However, I was surprised by the white flash and the production of a white product, which were reminiscent of the classic combustion of magnesium demonstration. This led to some research and my conclusions that follow. Read through to the end and you will find a video of the demo.

Big Ideas in AP Chemistry: Connections Among Thermodynamics and Equilibrium

I have a confession: thermodynamics is not my strong suit. The data set I got from the College Board confirmed my lack of confidence in the summer of 2015. With the hope of improvements, I spent some time revamping my thermo unit and I implemented it near the end of last school year. I will share an activity that I feel was quite formative for students and for me in making connections among thermodynamic principles and equilibrium.

 

PASCO Wireless Temperature Sensor, update on Classkick and with exams coming soon try High School Chemistry: Practice Tests and Flashcards by Varsity Tutors

This past week, as part of our Thermochemistry unit, my students were completing one of my favorite .  We were using calorimeters, dissolving ammonium nitrate, and my students were recording the change in temp