methyleneblue
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Using an erlenmeyer flask for refluxing
Hi all,
I'm going to be doing a Fischer-Speier Esterification tomorrow, probably some Isopropyl Acetate. My only issue is, and partially due to laziness, is
that I don't have a mantle yet, and can't be bothered setting up an oil bath on the hot plate for a round-bottom flask.
Is it possible to just stick an erlenmeyer underneath a condenser, sit it straight on the hot plate and reflux that way? Or does that do some
witchcraft to the reaction and stuff it up? 
PS: Yes, I am using glass joints. The flask and condenser are connected, not just sitting above one another.
[Edited on 29-3-2017 by methyleneblue]
MethyleneBlue.
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PirateDocBrown
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How do you propose keeping the vapor from escaping between the condenser and the flask? Or is it an Erlenmeyer with a glass joint?
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methyleneblue
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Woops. 
Yep, 24/40 glass joints all the way.
MethyleneBlue.
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j_sum1
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I don't see any particular issues. The only thing is that the shape of an Erlenmeyer lends itself to greater thermal stresses with uneven heating.
And you will get uneven heating. The Erlenmeyer will also tend to reflux in the flask -- which could be a good thing or a bad thing depending.
Bottom line, ok unless you are doing something high temp.
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methyleneblue
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Quote: Originally posted by j_sum1  | I don't see any particular issues. The only thing is that the shape of an Erlenmeyer lends itself to greater thermal stresses with uneven heating.
And you will get uneven heating. The Erlenmeyer will also tend to reflux in the flask -- which could be a good thing or a bad thing depending.
Bottom line, ok unless you are doing something high temp. |
Alright sounds good, Isopropyl Acetate boils at 89°C anyway so I should be fine.
Thanks.
MethyleneBlue.
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j_sum1
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Well at that temp you could easily rig up a water bath. Far less messy than an oil bath IMO and having a ceiling temperature and a bit of thermal
ballast makes the process easy to control.
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methyleneblue
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| Quote: Originally posted by j_sum1 | | Well at that temp you could easily rig up a water bath. Far less messy than an oil bath IMO and having a ceiling temperature and a bit of thermal
ballast makes the process easy to control. |
Ooo I like that idea.
Will also look into this. Thankyou! 
MethyleneBlue.
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XeonTheMGPony
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I've used brine solutions for this sort of work too, helps suppress waters boiling point making it higher. Some thing for ya to look into.
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methyleneblue
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| Quote: Originally posted by XeonTheMGPony | | I've used brine solutions for this sort of work too, helps suppress waters boiling point making it higher. Some thing for ya to look into.
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Are you talking about in the actual beaker? Because if so, wouldn't this react with the Alcohol, Carboxylic acid and Catalytic acid and do some crazy
reactions?
MethyleneBlue.
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Tsjerk
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He is talking about the water bath, it will be a bit safer towards boiling to dryness with the electrical heating set to the same output of heat . You
can also put more energy into the reaction, but I don't know if that is necessary. Especially if you use IPA in excess.
[Edited on 30-3-2017 by Tsjerk]
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PirateDocBrown
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Erlenmeyer, condenser, and hot plate are pretty much exactly how I do such things. Water bath, if the temp is low enough. Sometimes a flatbottom round
flask. But yeah, all 24/40.
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XeonTheMGPony
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| Quote: Originally posted by Tsjerk | He is talking about the water bath, it will be a bit safer towards boiling to dryness with the electrical heating set to the same output of heat . You
can also put more energy into the reaction, but I don't know if that is necessary. Especially if you use IPA in excess.
[Edited on 30-3-2017 by Tsjerk] |
You nailed it.
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