Sciencemadness Discussion Board

DIY Volumetric Flask?

cpman - 19-12-2013 at 17:57

Hello everyone.
I really like home chemistry, and have found that having a volumetric flask would be especially helpful, especially when preparing solutions of a known concentration and a known volume. Would there be any way to make a volumetric flask at home? I have some old glassware, and theoretically, I could turn them into a volumetric flask.
However, whenever I search anything like this on google, I just find instructions about how to USE a volumetric flask, not how to make one. I know how to use one of these flasks, but I'd like to know if I could make one at home.
Is this possible and/or feasible?

Thanks!

bfesser - 19-12-2013 at 18:01

It is feasible, but you must have a high-resolution balance or scale to calibrate it.

cpman - 19-12-2013 at 18:04

Ok. That would be one to at least the thousands if a gram or more, right?

Also, would I need a really accurate thermometer, right?

EDIT: Wow! Thanks for getting back to me so fast!

[Edited on 12-20-2013 by cpman]

[Edited on 12-20-2013 by cpman]

Zyklon-A - 19-12-2013 at 19:40

I found three pieces of glass-ware, that looked a lot like volumetric flaskes, and could be measured to measure quit accurately.

Maybe, post some pictures up, if I can find a camera.....

[Edited on 20-12-2013 by Zyklonb]

Dr.Bob - 20-12-2013 at 06:49

It all depends on what you are trying to do. For example, If you need to titrate something carefully, then a real volumetric flask is ideal for making the stock solutions, but you also need an accurate balance as well. But if you are simply running a reaction, and need a solution, often the exact volume is not quite as critical, so a simple graduated cylinder is sufficient for measuring the volume. But you can make a "volumetric" flask easily with a bottle or flask, some liquid and a balance, by simply filling the flask to a known weight of liquid (with a known density at a set temperature (like water which is about 1.0 g/ml, depending on temp) and then marking the height on the flask. That is how most volumetric flasks were made in the past, and likely still are made that way. But you can get real volumetric flasks used for pretty cheap, so it is not a big deal, maybe a few bucks each.

cpman - 20-12-2013 at 07:45

I'll try this. Because my house averages around 23 degrees C, I'll add 199.48 grams of water to a container, which should give exactly 200ml (actually just a TINY by less...)
Would that be the proper process?

DubaiAmateurRocketry - 20-12-2013 at 09:10

I had a scale up to 0.01 grams, and I made one of my own volumetric flask with that :p

Hexavalent - 20-12-2013 at 15:37

Volumetric flasks are readily and inexpensively available from many suppliers, and, for the resolution, accuracy and simplicity simple buying one provides, making one is simply pointless. I appreciate the importance of amateurs often making their own equipment, but the proverbial line has to be drawn somewhere.