Decorative beads are tested for the presence of iron pyrite, or FeS2, in an activity well-suited for the National Chemistry Week theme of "Chemistry Rocks!"
I have been in the lab conducting tests on the chemical and physical properties of various geological samples. In my investigations I’ve found that hematite is a particular mineral that is easy to acquire and quite amenable to experimentation.
Near the end of the school year we are all thinking about what we will do with our AP Chem students until the end of the semester. Last year I wrote about a post AP independent study activity that I use dealing with transition metal compounds. I still like it and use it. But this year I want to talk about a very involved lab that many of my colleagues are ignoring.
According to the app store description, Chemical Formula Challenge is "An educational game to improve your ability to form chemical formulas from chemical names. You can either play it yourself or challenge a friend". The app features different levels of play such as easy, normal, and hard regarding the difficulty of the ions. As an example, beryllium chloride is considered "easy" while lead II nitride is considered "hard". The app then gives the user several ions to choose from and the user must then select the correct number of ions needed to balance the formula correctly.
As our Gas Laws unit was coming to an end, it was time to create the test. As I thought of potential test questions that were both challenging and in alignment with the learning objectives we had previously identified for the unit, I was reminded of a multiple-choice question I had been shown in an old Modeling InstructionTM resource.
HCl and NaOH, a strong acid - strong base titration? Citric acid and NaOH, a weak, triprotic acid - strong base titration? Do your students standardize the NaOH solution as a first step?
After spending the start of the year using a modified version of the Modeling Instruction curriculum (density and physical properties, followed by gas laws, followed by energy and phase changes), we don’t actually start talking about what’s inside atoms until December. I love that by this point students are already familiar with some of the habits of mind needed to reason abstractly about atoms -- thinking proportionally, explaining macroscopic observations at the particle level -- and we are ready to layer on both more abstraction and the symbolic level. By January, we are ready to explore electron configurations.
This is the first isotope activity I have tried where the students can look inside the model that resembled the atom and find information that reinforced what an isotope actually is. Furthermore, the quantitative data forced them to examine beliefs about different types of averages and what the numbers really mean.
In this "Pick" I'll briefly describe how I use the ChemDraw iPad App for creating structures for my teaching. I also provide a link to a tutorial where I share some tips on how to get started using ChemDraw on your iPad.
For years my students would heat the hydrates in glassware, burn themselves, break the glassware and splatter salts and thus their data, all over the lab bench. A few years ago Bob Worley came up with a great microscale technique. Essentially, it takes a used bottle cap without the plastic and this is used as the dish. Next, there is about a three inch machine screw that goes through a drilled hole in the cap. A nut is placed on the screw to hold everything in place and cheap pliers are used to hold the entire assembly over the flame.