Drop Counters are AWESOME.
When given the choice between spending 20+ minutes manually entering volume data every 1 mL, or sitting back and watching it the data graph itself in 3 minutes or less, I’m going with the latter. Not only does the data come out great but it frees up the students to actually look at and analyze the data they’re collecting in real-time, rather than fiddling with stopcocks and reading burets.
They’re not cheap, but having one setup would be a great way to visualize and talk about the various regions of the graph as a class, and to ask and answer student-driven questions (Students can make predictions of how a SA/SB titrations would differ from SA/WB, WA/WB, and see if they were right). The Pasco version of the dropcounter also allows you to collect conductivity data simultaneously, which opens up more possibilities for whole-class inquiry and exploration.
That’s pretty much it. We worked in pairs completing lab kits for the 16 guided labs as produced by Flinn, Carolina, and Wards. The instructors wanted us to see if the labs met our expectations, if they could be completed in a reasonable time, and if they were AP-level. We’ll debrief thattomorrow. My initial impressions:
- The “sample data” provided in some teacher’s guides clearly cannot be obtained with the provided materials. One of the labs simply couldn’t be completed as written, or with reasonable modifications.
- I think some kits were thrown together in order to be released in time for the beginning of the ’13-14 school year.
- The convenience factor fades quickly. It is generally best to build your own kit from scratch. The AP manual itself, though it has flaws, has been a better resource than many of the kits.
On to day three…