Expert: Dr. Henry Boyter, Jr. - 9/17/2006

Question
I searched Google/Wikipedia and couldn't find the answer. I'm a Freshman in college, class is Chem 101 Lab.

On chemistry glassware, there are designations of TC or TD. I know that TC means "to contain" and TD means "to deliver" but what exactly does this mean when its found on a glassware? And what if neither of them are on a glassware? What would glassware that has this be used for?

PS. Need an answer by Monday night. If you didn't get to it by then, its ok. Disregard the question.

Thanks in advance if you can help me out. :-)

Answer
Another way to think about it.

TC = To Contain = To Store

TD = To Deliver = To Transfer

A 50 mL volumetric flask is never used to measure a volume of water and then transfer it into another container to make the solution.  You make the solution in the volumetric and you can store it there, thus TC.

But if you had a 50 mL pipet, you measure the 50 mL of water in it and transfer that volume into another container to make the solution.  You never make the solution in the pipet and you would never store anything in the pipet, thus TD.

There are containers that can be both, graduated cylinders for example, but grad cylinders are usually TD since you don't store in them, but some are made just for that purpose.