Fyndium
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Reaction vessel choosing?
How do you choose your reaction vessel for different purposes? Are some types better suitable for certain reactions? I see nurdrage is a prominent
user of erlenmeyers, while I use exclusively round bottom flasks.
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Maurice VD 37
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It depends of what you are doing. Usually beakers are useful for ordinary reactions with aqueous solutions. Erlenmeyers are useful for titrations,
because the solution must be continuous stirred, and this goes better with erlenmeyers. Round bottom flasks are better if you want to heat it with
boiling water. But it has the disadvantage that it cannot be put on a desk.
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Belowzero
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Main difference being that erlemeyers can't handle vacuum.
Vaccuum erlemeyers are not suitable for heating and as such we use round bottom flasks.
RBF's with multiple necks are useful for all sorts of reactions something which is more difficult with erlemeyers.
One of the downsides is the use of a heating mantle, it will have to fit the flask and one would need a different one for all sizes which is
expensive, since I own only one I often use erlemeyers for the simple reason of having more contact surface with the heatsource.
I also tend to use the cheapest glass since accidents happen, I'd rather break something cheaper when I can get away with it, wear should be
considered too especially when materials are know to attack glass.
Stirbars are a consideration too, heating mantles with stirring function are quite expensive which makes a hotplate + erlemeyer the logical next best
thing.
There is no one size fits all answer here but in my case too erlemeyers are the workhorses and RBF's are used in more specialized situations.
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Herr Haber
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Beakers, flat or round bottom flask depending on the reaction.
I dont use Erlenmeyers as reaction vessels but rather to dissolve something in a solvent, prepare reagents and such.
The spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words 'act upon' meant. - Ira Remsen
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MidLifeChemist
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This is a great question and I look forward to seeing more answers.
I'm putting together my home lab and I just ordered my erlenmeyer flasks, beakers, and hot-plate stirrer.
However, at some point soon I'm going to want to do a simple distillation, and I've love to be able to do it with my hotplate / stirrer and erlenmeyer
flasks. I need to look at the nurdrage and nileRed videos more closely to see how they do their distillations and how I can do them in an economical
way. Ideally I could use my existing hotplate / stirrer and not have to get a separate heating mantle.
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greenlight
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Beakers: Most reactions that require mixing and heating or cooling.
Conicals: Titrations and making up saturated solutions.
Round bottom: Distillations and reflux.
The only use for an atomic bomb is to keep somebody else from using one.
George Wald
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Fyndium
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I actually have never carried a single reaction in a beaker, except some metathesis tests. I usually use them to roughly measure and to transfer
reagents. I have always used rb flasks for everything, although one reason could be that I did not own erlenmeyers before recent times. Beakers have
the issue of evaporation and larger odor emission aspect. I find that I use my newly purchased erlenmeyers for transfering, mixing and receiving of
reagents, but carry out at least all distillations in rbf because my setup is more prepared for them (heating baths, etc). I really don't like the
idea of heating any glassware over direct hotplate/flame.
I highly prefer closed vessel designs. I feel I have better control over the reaction and reagents.
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RogueRose
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Quote: Originally posted by Belowzero  | Main difference being that erlemeyers can't handle vacuum.
Vaccuum erlemeyers are not suitable for heating and as such we use round bottom flasks.
RBF's with multiple necks are useful for all sorts of reactions something which is more difficult with erlemeyers.
One of the downsides is the use of a heating mantle, it will have to fit the flask and one would need a different one for all sizes which is
expensive, since I own only one I often use erlemeyers for the simple reason of having more contact surface with the heatsource.
I also tend to use the cheapest glass since accidents happen, I'd rather break something cheaper when I can get away with it, wear should be
considered too especially when materials are know to attack glass.
Stirbars are a consideration too, heating mantles with stirring function are quite expensive which makes a hotplate + erlemeyer the logical next best
thing.
There is no one size fits all answer here but in my case too erlemeyers are the workhorses and RBF's are used in more specialized situations.
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I have to question the statement that Erlynmeyer flasks can't handle vacuum. From what I know, they are the primary flasks used for vacuum
filtration. You see more of these flasks with a vacuum port on the side than any other flask made. They also make these in thicker glass more often
than any other flask that I have seen (especially when it has a vacuum port).
I use my erlynmeyers for vacuum filtration all the time, as well as heating and use the side port for either vacuum or gas extraction and have never
had a problem. IDK if I've just been lucky up to this point or what.
In fact if you buy a flask filtration setup, there is a very high probability that they will provide an erlynmeyer flask with the side vacuum port.
I've actually never seen any other type of flask included in these packages.
What do others think about this?
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