When inverting a graduated cylinder, why do we have to correct the volume by subtracting 0.2 mL?

Question

My TA said that it's because there is water in the lip of the cylinder, so we have to account for that. This doesn't make any sense to me, so I'm looking for an alternative explanation. Thanks!

Answer 1

It would help if we knew what type of experiment you were doing where you inverted the cylinder. Was it collecting a gas? It so, then you need to subtract the volume of the water vapor at the particular temperature that you are using. That may have been 02 ml, I don't know. If it's for some other experiment, we'd need more details.