Science Buddies: "Ask an Expert"

I am doing the yeast busters: stopping fungus in its tracks with antifungal medicines project for my science project and I'm not sure how to put the plastic tubing inside the inverted graduated cylinder that's in water. Please help!

Hello HarrietAS,

I'm assuming that you are working on the project described here:

https://www.sciencebuddies.org/science- ... p012.shtml

The graduated cylinder is used to collect carbon dioxide produced by the yeast. The carbon dioxide coming through the plastic tubing will displace some of the water in the graduated cylinder. You can gauge the amount of carbon dioxide produced by observing the water level in the cylinder.

It would be best to make sure that the graduated cylinder is vertical and full of water when you start your experiment. The end of the plastic tubing should be placed a few centimeters inside the graduated cylinder.

My suggestion is to place the water-filled graduated cylinder so that the open end of the cylinder is several centimeters from the bottom of your water container. That should give you some room to get the tubing into the cylinder.

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

A. Norman