The first few experiments and labs that I use to start the year off are more like “probes”. I am trying to figure out the strong and weak points for my students. I have found a couple of things we can work on. The two major areas are observations and communication. We need to work on writing sentences that use data and background information to support the theories students develop.
Red dye #40 found in strawberry Kool-Aid and various cloth fibers can be used in a very simple experiment that can teach students about intermolecular forces. A video is included that describes the experiment and analysis of results.
Undergraduates Need a Safety Education is the title found in the commentary section of the September 2016 Journal of Chemical Education. It is written by Robert H. Hill Jr and it explains the lack of safety education in chemistry curriculum. As I read this, I thought back to my safety education that prepared me for my role as a high school chemistry teacher and felt I was very fortunate to have had an undergradutae class that was specifically designed to teach chemical safety.
The purpose of a lab practicum is to assess a student’s understanding of the content by completing a hands-on challenge. These assessments focus more on problem-solving skills than technique.
I started teaching in a chronological order when I began using Modeling Instruction in my classroom. During the second year of "walking in the footprints of the scientists that came before us", I wanted my students to see where they were walking and a colleague and I came up with the idea of making footprints for each of those scientists and posting them on a timeline.
Each year we do an activity that involves Archimedes principle. You might wonder...why do this in chemistry? Leading up to the activity, students do a series of labs and activities that involve measuring, accuracy, precision, significant numbers and density. The culminating guided inquiry activity takes place by which students take an object, find the volume in multiple fluids and find the mass in multiple fluids. An examination of class data starts to show that the volume of a solid does not change in fluids but the mass in air and the mass in different fluids are different.
There has been considerable discussion lately of standard based teaching. Essentially, a teacher has a set of standards and they teach to these standards. The idea is that instead of saying "Hey, you got a C on this test, time to move on..." a teacher would say "This is the standard...you can exceed it, meet it or you can approach it...the goal is to meet or exceed the standard and if you do not, keep trying." Here is an example...we were covering gas laws in my class. I asked seven questions about conceptual ideas concerning gas laws.
ChemEd X recently made a Call for Contributions soliciting input regarding the big ideas being put forth by organizations like AP. The first thing that came to mind was a lab I modified that is centered around making connections between topics. Admittedly, this lab is not a "big idea" per se. Rather, it's the big idea that students should be able to make connections between topics we study to solve problems. So in this blog post, I would like to share a lab activity that relies on these connections - between stoichiometry, esterification, equilibrium, kinetics, titrations and uncertainty of calculations. I will also share the resources I have created to support my students through the process of working through these calculations.
Three class periods
Day 1: setup of equilibrium mixture; roughly 30 minutes
Day 2: titration of equilibrium mixture (approximately 1 week after Day 1); roughly 60 minutes
Day 3: calculations; variable time required - typically 30-90 minutes depending on the student group