In this lesson students have a chance to practice what they learned about reaction rates through performing a lab activity.
To begin this lesson I go over the lab with students.
In this section of the lesson students are expected to perform the alka seltzer and rates lab.
When they get up to their stations they first finish their data tables, and then begin the lab activity. This is a movie showing one group of students performing one of their trials.
As students are working I walk around and check for several things...
As students complete the lab I have them begin to work on the analysis questions. When all students are done with the lab and working on the analysis questions I have them pause so that we can work on the extension together.
When most students have completed the lab I lead them in performing the extension activity. This is found on the last page of their alka seltzer and rates lab.
For this extension students read an article discussing how aspirin should be taken if someone is having a heart attack. Basically, it says that the aspirin should be chewed as that it gets into the bloodstream and works faster. The goal is for students to come up with a claim that the article gives similar results as their lab because they both show that by increasing surface area that reactions happen faster.
This is a movie of me going over this with one class.
When students complete their labs I have them turn them in and I grade them using the alka seltzer lab rubric.
Most of my students missed at least one point, and most forgot to revisit their predictions. These are several examples of some graded labs which show some of the common mistakes by students.
In this first example the student had an incorrect prediction for their prelab, did not refer back to their predictions in the analysis section #1, and did not really come up with a claim in regards to evidence from their lab in the extension.
In this second example the student did not refer back to their predictions when doing analysis part 1, and did not use evidence in the extension section.
In this third example the student did a good job but still did not refer back to their predictions in the first part of their analysis.
Finally in this fourth example the student also did a good job but did not refer back to their predictions int he first part of their analysis.
Because so many students forgot to go back to their predictions I feel that I need to do a better job of helping students with this next time. Therefore, I made some changes to the lab which I discuss in the reflection, Common Confusions with the Lab.