Friday 8.27.10

What we tried to figure out in class today was, how long it would take an alka-seltzer rocket to react as quickly as possible while placed in a certain amount of water.

MATERIALS

* 1 or 2 Alka-Seltzer
* 1 Film Canister
* Water supply
* Safety Goggles
* Stop Watch or Clock

First, we filled in our film canister with cold water about a quarter way, then we placed in two alka seltzer in the canister. After that, we closed the film canister and timed to see how long it took for the alka seltzer to react. On our first attempt, it only took about 10 seconds to react. Next, we retried the first step but this time we filled it in about half way. This attempt took about 15 seconds for the alka seltzer to react. On our third attempt, we filled up the film canister with about 75 percent of water in it, this only took about 7 seconds. We then later tried to flip the canister so that the top would be resting on the bottom. With the water only 75 percent of the way filled, this only took about 13 seconds to react.

Independent Variables

* amount of water in the film canister
* either 1 or 2 alka-seltzers in the canister
* cold or hot water added in the canister

Dependent Variables

* how long it took for the the film canister's cap to pop

Controlled Variables

* Temperature of the water
* amount of alka seltzer's in the canister
* how much water was put in
* flipped or not

It might be different for other groups, but the amount of water that made the fastest rocket was when the water was 75 percent full.

http://www.stevespanglerscience.com/img/cache/bcb9b8db117ee64376aedaf7af3595ca/03-06-06-alkaseltzer_rocket-08.jpg
http://www.chem.fsu.edu/chemlab/chm1050lmanual/masspercent/alkaseltzer.jpg
http://i.ehow.com/images/a04/qp/a8/build-alkaseltzer-popper-200X200.jpg