will this be on the test?
This dirty secret about chemistry lab is: They. Never. Work. And chemistry teachers are of two ilk: 1) Make It Work (a la Tim Gunn) and 2) Good Enough. Fortunately, my current (and favorite) chemistry teacher is of the Good Enough variety.
We were doing a fairly simple specific heat calculation today, and we just couldn't get the bloody mixture to achieve the maximum temperature change. All you do is mix two things together at varying volumes and record the temperatures, and figure out where the max. is. Then you calculate a bunch of other crap based on that. It's an exercise in precision and stoichiometry, which is the chemistry word for "maths." We were supposed to get about a 7 degree change, and only got to five, which is kind of a big difference.
The trick of it is to have a reason why it didn't work. I came up with heat loss through the top of the container, the insulation on the container maybe being not quite up to snuff, and of course, the old standby -- this thermometer isn't very precise.
Actually, the scary thing is when things DO work perfectly. Teachers never buy flawless data. I've been asked to redo labs because of suspiciously clean data more often than if I totally bungled the thing. The graph we came up with last week was a thing of beauty, not one outlier. But I knew enough to jimmy one data point over a bit so the ol' line-of-best-fit wouldn't be so perfect. I guess teachers just expect us to be morons. Which, let's face it, we are.
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