Welcome to the Chemical Education Xchange (ChemEd X)! We hope to strengthen the community of chemistry educators by providing learning resources and forums for discussion and collaboration right here at this site. Take a look, and join in.
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. They also use the density of the fluid and the volume of the fluid displaced by the submerged mass to find the mass of the fluid displaced. The hope is to guide student's thinking to help them understand that the apparent loss of mass, or the buoyant force of the fluid against the mass is the same as the mass of the fluid displaced. In theory, this should be a great lab. The reality is that the instruments we have are less then ideal, it is tough to guide students with bad data and there are many connections that need to be made.
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.
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
How do teachers encourage building individual lab skills in classes of over 30 students where labs are done in groups of five or six students? My science department collaborates daily, and we have been discussing this concern for a few years now. Many trials and errors have occurred.
This school year my district is launching a 1:1 Chromebook initiative. 6th and 9th graders will receive their Chromebooks next semester as part of the rollout. In the meantime, I continue to have access to my Chromebook cart from the Blending Learning pilot I participated in last school year. My goal is to incorporate even more tech use when appropriate; so far, I have increased Chromebook use in my classroom for things like warm up questions, EdPuzzles, and quizzes. My experience with quizzes has been especially interesting.
Engaging Student Interest and Inquiry
The September 2016 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: copper chemistry; safety; using brewing to teach chemistry; 3D-printed models; learning using games; open-ended approaches to teaching; innovative methods to teach biochemistry; polymer chemistry; organic synthesis labs; teaching physical chemistry; chemistry field trips.
In a previous post I talked about an equation balancing lab that I have been doing with my students involving building molecular models. This time I would like to focus on another lab that I have developed for my model kits.
15 minutes prep and 30 minutes for students to observe the molecules.
College Board offers an excellent online resource for teachers and students. It's not free, but my school district pays the bill. AP Insight provides curriculum outlines, teaching ideas and resources, student handouts, and digitally-graded assessments. I have elected to begin using the resources in first semester honors chemistry.