Reef Chemistry Question of the Day #159 Measuring Volume

[Randy Holmes-Farley]

Reef Chemistry Question of the Day [HASHTAG]#159[/HASHTAG]

Which of the following types of glassware is typically designed to give the most accurate measure of volume? I show only the picture.

A.

B.

C.

D.

Good luck!
































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[Wiz]

I wanna say a because you see flasks in science. Lol my my guess is c simply because my instinct tells me so. Lol that's my professional opinion ;-)

 

[redfishbluefish]

Oops....double post for some reason....sorry

 

[redfishbluefish]

You left out pycnometers.....which we had to buy when I took chemistry in college. I still have it somewhere in the house, but I don't know where. Mine looked similar to this one:

Since pycnometer isn't one of the choices, I'll go with B, volumetric flask.

 

[ksfulk]

B Volumetric Flasks

 

[human]

B. volumetric flask

 

[JimWelsh]

B. Volumetric flasks

 

[SethOF]

C. The measuring cylinder

 

[Randy Holmes-Farley]

You left out pycnometers.....which we had to buy when I took chemistry in college. I still have it somewhere in the house, but I don't know where. Mine looked similar to this one:

Since pycnometer isn't one of the choices, I'll go with B, volumetric flask.

You lost your pycnometer? How do you live with yourself?

 

[redfishbluefish]

You lost your pycnometer? How do you live with yourself?

Density free!

 

[Lynn52]

B volumetric flask

 

[hart24601]

Well I guess it depends on what glassware you have and how much you need to measure! Volumetric flasks are great if that is the amount you need... but if you want 100ml and have a 250ml volumetric flask and a 250ml graduated cylinder good luck with using the volumetric flask!

 

[Sabellafella]

C

 

[john.m.cole3]

C due to the consistent shape of the cylinder over the abnormal shape of the flask

 

[Bruce Burnett]

I figure any certified graduated glass flask is good a cylinder is easier but any are only good if they fit what range you are needing

 

[KingBlingTX]

C- graduated cylinders

 

[ksanfranfan]

Gonna go with C. Graduated cylinder as well.

 

[McGee]

B

 

[cypho]

Precision is determined by the diameter at the fill line (and proper calibration). The smaller the diameter the more precise the measurement.

The only difference between C and D is that D has a larger diameter, so D is inherently out.

The difference between A and B is that the fill line on A is below the narrow point, while the fill line on B is at the narrow point. So A is out too.

B and C both have the fill line at a narrow point. So assuming the diameter of the necks are the same, they will be equally precise. Although nothing else matters when it comes to accuracy, but not all designs are equally practical.

You can make a 1 gallon container with design B and have a 1 inch diameter neck and be very practical and accurate - it would look something like a milk jug. Design C with a 1 inch neck would be just as accurate, but it would be 24 feet tall (Is my math right? 231 / (3.14*0.5^2) /12 ). Not at all practical.

So assuming you your container both an accurate and practical, go with B.

 

[PatW]

B volumetric flasks.