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.
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For a recent unit on organic chemistry for my IB students, I tried something new. I gave them a handout with a list of organic compounds (by class/functional group) and a list of mechanisms and reaction types. Their task (in small groups), using either butcher paper or a large whiteboard, was to create a flow chart of reaction pathways.
It is becoming increasingly important for citizens to understand various concepts related to climate change and global warming. This post describes several chemical concepts that are pertinent to these issues, in the hopes that teachers of science and chemistry can introduce the topic of climate change into their classrooms and everyday discussions.
To grasp the concept of oxidation and reduction reactions, I have my high school students write half reactions to show the loss and gain of electrons by the substances being oxidized and reduced. To help with this concept, I developed a quick lab activity involving the reaction between magnesium metal and dilute hydrochloric acid, which in turn led to the students collecting the hydrogen gas and then testing for its presence.
It’s the end of one semester and the beginning of another. Final exam week. For the first time in my teaching career, I had my grades caught up and posted prior to the beginning of final exams. This gave me time to reflect and plan ahead.
Whether you are introducing collision theory or something more demanding like reaction order, the reaction between sodium thiosulfate—Na2S2O3 and hydrochloric acid can provide a consistent, accurate, and engaging opportunity for investigating these topics.
Students will build models of isomers while the instructor walks around from station to station to critique the models. If the model is incorrect, the students rebuild until they get it right. The paper that accompanies this assignment is very easy to grade.
one 50 minute class
There are many places online to build a DIY Hoffman apparatus. The ACS offers an electrolysis of water lesson that includes a hand made Hoffman apparatus(link is external) as part of a unit on energy that I used as a resource.
The solution to Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice is presented. Why does liquid nitrogen launch the bucket so much higher than dry ice and water?
Looking over my student's papers, there may have been more misconceptions created because of the way I planned the curriculum. In all of the experiments students can see and observe that not all of the crystals or material dissolves yet the water starts to conduct. In their minds there is evidence that they believe either something DOES dissolve or it does NOT. Clearly, partial dissolving is initially too much to consider.