As part of the grade 12 equilibrium unit, I have my students perform a very traditional lab activity demonstrating Le Châtelier's principle. They rotate through a series of stations where they use a semi-microlab approach to investigate a different equilibrium system at each one.
In this article two example applications of gravimetric titration — acid content of fruit juices/soft drinks and pH titration curves — are presented. Both are suitable for laboratory experiments in senior secondary school chemistry courses or in college general chemistry courses.
This is a reprint from the February 2015 issue of Chem 13 News.
A couple of years ago, with the re-write of the AP Chemistry test and the increased focus on inquiry...
This is a continuation of the Thought labs used as review for AP Chemistry. This style of review allows students to incorporate the skills they have acquired throughout their course experience in AP Chemistry while providing a platform for them to increase their comfort level in situations where they are asked to apply their learning to a new lab setting.
The Poly Density Bottle1 is a fascinating demonstration primarily due to the phenomena being counterintuitive to what one would expect. The bottle containing white and blue beads suspended in a clear and colorless liquid is shaken vigorously, distributing the beads randomly throughout.
Equilibrium is a challenging topic for high school chemistry students to understand. This year I decided to tackle the conceptual understanding of equilibrium first with three different analogies and a Process Oriented Guided Inquiry Learning (POGIL) activity before even mentioning the words "equilibrium expression".
Your students may find it interesting to determine and compare the acid content of individual sour hard candies. In addition to doing the titration analysis and the calculations, reported as the percent by mass of citric acid, students can learn about the technology of candy making.
The inspiration for making pictures from droplets of chemicals first came from a Chemistry Club session at our school.
We know that acids dissolve our pearly whites, but where does this acid come from and what chemistry is really going on in our mouths to make this happen? If your mouth hosts biofilms of certain bacteria, especially Streptococcus mutans that are feeding off sugars, the teeth will be in contact with acid.