What are we doing to help kids achieve?
I don't know why I tend to get OCD over "rates" labs. Somehow...I just think they are cool. Students can change a wide variety of conditions and they see stuff "happen". Sometimes I think as a teacher I am clouded by my judgement of what I want or think is cool and forget what we do is about student learning.
I did have a rates microscale lab that worked really well. (As a matter of fact...about this same time last year I wrote about it here.) It worked well on several levels and each year I try to get a few more "bugs" out of the process. But sometimes, I have a hard time leaving "well enough" alone. I went to a regional ACS meeting this summer and some teachers were demonstrating "green" chemistry. I found a published rates lab using vitamin C, peroxide and iodine solution....all items I could purchase from the store. I thought it would be great to have students do a lab that would show the concepts with common household items bought at a store. In true science teacher fashion, I tried the lab before the students did. I substituted "betadiene" iodine solution instead of "iodine" tincture to save some money. It worked. And then there was lab day...
Honestly...I am not sure what happen. It may have been some type of contamination or it could be I just majorly messed something up. It was a disaster. There was little to no correlation for some classes. I am still not 100% sure where the mistake happened. So, what do you do when you have a disaster lab day?
First, I was honest with the students. I explained why I switched labs from last year and what I was hoping they were going to learn. They were great with the idea. We all talked about how sometimes science is hard and the experiment does not always go as planned. Second, I realized that sometimes things just do not go well. The good news is that no matter how bad the experiment or demonstration fails, the students are probably coming back the next day and every new day is an opportunity to learn from our previous mistakes and simply begin again.
Have you had a bad lab day recently? Don't get down on yourself too much. We are all human. Try to use the experience as a learning opportunity for yourself and for your students.