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.
Most chemistry teachers I know do flame tests with their students. It ties in well with many topics, is colorful and the kids enjoy seeing the colors and burning stuff. There are many applications. For years I always mentioned that astronomers use the idea of the flame test. They simply look at stars and examine the spectra from the light of these stars. They then match the spectra with the elements and then they can see and infer what elements are millions of light years away. I always mentioned this but never was able to demonstrate it.
Tom Kuntzleman loves to share chemical mysteries and that inspired me to create a list of mysteries that are appropriate for the main topics covered in IB Chemistry. In this blog post I'd like to share some detail about how I modified the mystery of the burning water.
Isotopes Matter is a digital learning tool, developed by IUPAC Isotopic Periodic Table, designed to explain isotopes as well as their importance. This resource incorporates mass spectroscopy data into each of the key ideas as well as provides multiple examples as to how varying isotopes are commonly used.
Is it possible to use materials found in high school chemistry labs to extract and subsequently detect cocaine on dollar bills? Let me know what you think after reading this blog post!
