This year's stoichiometry test has come and gone with less than thrilling results. We're okay on unit conversions, but when we add that extra step of using the balanced reaction to describe ratios between substances, things fall apart.

This is a tough concept that I struggle to teach well. I don't know if more labs/hands on will help - I added one this year and I didn't see better results. Granted, we had several weather interruptions last week that preceeded the test, but even today, there are still large gaps in understanding that I need to do some digging into to figure out what is going on. My hunch tells me that is a "will" issue instead of "skill" issue for 90% of students.

My students were incredible with the iodine clock lab. Given the complexity of the procedure and the accuracy with which they needed to measure, they rose to the occasion.

Everyone split into their groups and immediately read the materials lists and read the procedure before even getting chemicals. They measured stock, asked good questions ("Is tap water okay?") and delegated tasks.

The soft click of glassware and hush of partners cooperating was musical.

I wrestled hard with an iodine clock reaction this week. I haven't taught kinetics in many years, so I was re-learning a lot as I went. I'm still confused a little by the data I got vs what I expected, but I think it's a case of the real world being much messier than practice problems.