Blogs

Chemistry in a Bottle

Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies. Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle. The plastic pieces display curious floating and sinking behavior when the bottle is shaken. 

What to do after AP? Build and test simple dye-sensitized solar cells!

Have you considered having your students make solar cells? If your AP kids can understand batteries, solar cells are a logical next step. I usually do independent projects after AP along with final presentations, but I stumbled upon this activity the other day and my mind exploded in excitement and thought I would share. In the future, I would definitely do this with my students!

Using Visual BCA Tables to Teach Limiting Reactants

A few months ago I was searching the internet, looking for a better way to teach stoichiometry to my pre-AP chemistry students. While my methods of dimensional analysis “got the job done” for most students, I would still always lose students and many lacked true understanding of what was happening in the reaction. I wanted to try something new that would promote a better chemical understanding. In my search for this elusive stoichiometry method, I came across Dena Leggett’s ChemEd X blog post entitled “Doc Save Everyone”, as well as other posts about BCA tables from Lauren Stewart, Lowell Thomson, and Larry Dukerich. 

You Are Invited: Chemistry Instruction for the Next Generation

ChemEd X and the Journal of Chemical Education (JCE) are collaborating to offer a virtual conference like most have never seen before. It is not a webinar. You do not have to schedule specific hours to view a live presentation. I think of it as similar to a virtual book/journal club with the added benefit of having the author leading it. In this case, authors were selected from among those who have published recent articles, activities and research in JCE on the topic of student-centered instruction in chemistry. The theme of this inaugural conference is Chemistry Instruction for the Next Generation.

Compiling Student Data

To assist in grading the lab results for this and other quantitative labs that we did, I created Excel spreadsheets where the students’ results could be entered. The spreadsheet then did all the required calculations and compared the students’ results to the theoretical value. This made grading the lab reports much quicker and more accurate, flagged incorrect student calculations, allowed a much more complete discussion of the lab results and permitted “what if” questions to be discussed.

Shorten Grading Time with this Stoichiometry Tool

As many chemistry teachers know, grading lab reports can be a very time-consuming task. For me, the lab report that has required the most time to grade is a stoichiometry lab that I have been doing the past couple years. Though we do at least four “formal” lab reports each year, what makes this one different is that it involves a lot more calculations and subsequent results than any of our other labs. Regardless of how well they organized their report or wrote their conclusions, their results need to be checked for accuracy. This takes time. Even after eventually being able to generally eyeball their work, it still takes more time than I would like. So, this year I finally decided to sit down and generate a tool for me to expedite this process—the stoichiometry calculator.