Chemistry in a Bottle

density bottles

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. You can find out even more about how a colleague and I have explored the experiment by attending our session within the ChemEd X Conference: Chemistry Education for the Next Generation.

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

solar cell with clips

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!

Demonstration: Reaction of Magnesium and Silver Nitrate

Starting materials for demonstration

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.

Time required: 

30 minutes including preparation time.

Rates Lab and what to do when things don't work....

Rates Lab

I really enjoy doing reaction rate lab with my students. I often change them up so that I use a different version or tweak an old version. This can lead to a variety of outcomes. Sometimes trying something new or tweaking something that went well before can go wrong.

Using Visual BCA Tables to Teach Limiting Reactants

picture of materials and WS

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

Chemistry Instruction for the Next Generation graphic

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.

A replacement Maxwell-Boltzmann Distribution Simulation

Maxwell-Boltzmann Distribution Simulation from Wolfram

In this Pick, I will share a replacement simulation I found for studying Maxwell-Boltzmann Distribution Curves, as the previous online simulation I used was no longer working due to Java issues.

Compiling Student Data

Excel file for 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.