The Carbon Dioxide Experiment
Reported by David, Betsy, and Eve
Our experiment in science was to prove that fish exhale carbon dioxide.
We did this by placing a goldfish in a cup of water, then we added BTB which indicates carbon dioxide.
BTB starts as a shade of blue. When BTB interacts with carbon dioxide, it turns to a shade of yellow, depending on how much BTB was put in the water.
After about an hour, we looked at the cup with BTB, water, and the goldfish. Believe it or not, our experiment worked! The water was now a bright yellow!
4 responses so far ↓
BM // Oct 22nd 2009 at 3:57 pm
Wow I didnt know that!
[Reply]
David // Oct 22nd 2009 at 5:26 pm
My question is whether there was a “control” activity along with your “experiment” activity. For example, do we know for sure that the BTB would have reacted differently after a half hour in water with no fish? I think the scientific method requires both “control” and “experiment” (if I recall correctly from fourth grade science). Sounds like a great activity and I look forward to learning more about this.
[Reply]
mkreul // Oct 22nd 2009 at 7:40 pm
Fourth graders, I am wondering what BTB is. Does it have a scientific name? Do scientists use it for other purposes?
Ms. Kreul
[Reply]
4A student Reply:
October 26th, 2009 at 11:12 am
@mkreul,
The scientific name for BTB is bromothymol blue. Scientists do use BTB for other purposes but I’m not sure how.
[Reply]
Leave a Comment