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.
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.
My students and I tend to have good experiences with a hydrate inquiry lab that I have "tweaked" (see the previous blog). Essentially, my students have some practice with hydrates in the lab and then they are provided an unknown hydrate. They must separate off the water by heating and calculate the mass of the anhydrous salt and container before they come up and put it on the scale. As an added twist, they must also ask me a question about what information they need from me to calculate the mole to mole ratio of the salt to water.
How do you support growth in your students’ writing and communication over time? There are so many things: Claim, Evidence, Reasoning (CER) scaffolds, sentence starters, and more. How might all of these tools used in introductory courses come together in an upper-level course? In this post, I will focus upon my AP Chemistry lab notebook set-up.
This week, one of my students alerted me to some mobile apps featuring chemistry. One, in particular, seems to be mostly free and incorporates a hands-on approach to conducting virtual laboratory experiments. The app is called BEAKER - Mix Chemicals and is offered by THIX on the Apple and Google Play Stores. My student demonstrated how the app works and I gotta say - it's pretty sleek.
The chemistry of the Sky Blue dye found in McCormick's Color From Nature food colors is explored. This is part one of a three-part series in which the chemistry of McCormick's Color From Nature food colors is presented.
The lab was a success as I watched startled students produce the so-called barking dog sound as they combusted the hydrogen gas in their inverted test tubes.
You probably know what happens when you place dry ice in water. Do you know what happens when dry ice is placed in acetone or glycerin? Read this and find out!
I have used several different versions of the Silver Mirror or Tollen's Test lab. I am sharing the method that has proven to be the most reliable for me. The solutions should be made fresh, the directions must be followed closely and timing is very important. I like the fact that relatively small amounts of the chemicals are required, but as always you must be vigilant with safety precautions.
Have you ever wondered where the cloud comes from when dry ice is placed in water? If you think the answer is “atmospheric water vapor”, be sure to read this post because experimental evidence suggests that this explanation is wrong.