Science Buddies: "Ask an Expert"

Hello so I am doing this science fair project:
https://www.sciencebuddies.org/science- ... #procedure

and I have a question, so basically I don't understand how exactly I'm supposed to measure the amount of carbon dioxide it says that after I make the yeast solution I put it into a bottle but then what? I also don't understand how exactly i'm growing yeast (sry I know its a lot)
- I need help ASAP thanks

Hello DeemaaaO,

In this experiment you collect the carbon dioxide in an inverted graduated cylinder that is initially filled with water. The carbon dioxide from the yeast metabolism displaces some of the water in the cylinder. The amount of carbon dioxide in the cylinder is indicated by the height of the water. The graduations on the cylinder can be used to gauge the water height. See steps 1 and 2 under “Setting Up the Gas Collection Apparatus” in the project procedure for more details.

The amount of carbon dioxide produced is an indication of the yeast metabolism. Metabolism differs with and without the presence of oxygen. So you might expect to collect different amounts of carbon dioxide with and without aeration.

I hope this helps. Please ask again if you have more questions.

A. Norman

Hello and THANK YOU SO MUCH for your help!!