Monday, June 9, 2008

Science Camp 2008: Day 1

Science Camp Day one is in the books. I am beat. Every year I do this I am in awe of teachers that do this for a living. It take a lot of effort to keep 5-8th focused.

Today (in Chemistry) we started with some food chemistry. We did the classic peanut burning lab.

After ensuring no one was allergic to peanuts, we measure the caloric content in peanuts. A unfolded paper clip is stuck into a large cork. The other end is used to impale a peanut. The peanut is ignited using a bunsen burner. The burning peanut is placed under an 8 oz pop can filled with ice until the peanut stops burning. The amount of ice that melts is used to determined how many calories of heat the burning peanut gave off. I help them with the calculations and then we discuss the experiment design and how it could be improved.

During this discussion, I try to explain the difference between a calorie and a Calorie (this has always annoyed me). One food Calorie (capital 'C') is the same as one kilocalorie (little 'c'). So, 1 Calorie = 1000 calories. That is so annoying.

After doing the peanut, we repeat using Cheetos. Let me tell you, Cheetos burn very well. The data is not as good because the large flame makes "catching" the heat difficult since much of the flame goes around the can. But, the students love to see the big fire.

When all was said and done, the values we measured were pretty close to the package values, but typically 10-15% low. This makes sense, since there are significant flaws in the experimental design. However, that is also the point. I want the campers to identify the flaws.

The demo I did today was the "methanol cannon." About 10 mL of Methanol is placed in a plastic bottle (any size up to 20 L). The bottle is agitated. A match is added to the neck of the bottle and the methanol vapors ignite. This makes an impressive fire ball in the container. An attempt to repeat the demo fails and a discussion on the role of oxygen in combustion ensues. As an added twist adding boric acid makes the flame green. For the best results, I use a 20 L plastic water bottle. In small rooms I have blown ceiling tiles out of place.

SCIENCE!!!!!!!!!!!

2 comments:

the indefatigable mjenks said...

I was confused for a moment, for as anyone who has ever tried to "wet" Pd/C for a hydrogenation will tell you (or any unfortunate open-wheel racer, for that matter), methanol burns with a colorless flame.

The green flame is a nice touch. Did anyone yell "Bitchin'", cause I would have.

Chemgeek said...

The kids now days use words I don't always recognize. I do know that "bitchin'" was not one of them.