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mbrown3391
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| Quote: | Originally posted by Klute
If you heat methanol without good agitation, there will be vapors evolving but no boiling, and the minute you hardly move the flask, a volvano will
spit up your condenser...
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The mixture was already boiling when i took it off the burner. if i had seen the boiling stop i would have expected a superheated solution.
i will however get a hotplate with magnetic stirrer before i try the actual reaction.
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Nicodem
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Your experience is both the sum of what you were already told about your own attitude and the confirmation that irresponsible people should stay away
from chemistry (or at least mature first).
You said you used a BURNER, only now you change your mind when other members told you how crazy that is.
I bet you did not even use any boiling chips or else you would not experience the delights of a high boiling liquid superheating.
And accident was only while trying to concentrate your solution. I dare not to think what you will do while doing the hydrolysis. Are we going to hear
about fumes going into flames, flasks cracking, suckbacks of HCl into boiling KOH?
Look, it is all very nice that you are interested in chemistry (at least I hope you are) and I would encourage you 100% if you would only show some
maturity. But it is obviously from your posting style that you are simply lazy, don't think about what you are doing, purposefully ignore theory, have
no experience with simpler procedures, don't understand the information already provided to you... and so on. Please reconsider and first obtain some
practical and theoretical skills by performing some simple reactions and read some books and articles. Maybe one day you will not only learn to use
the shift key on your keyboard, but even understand the mechanisms of the chemical transformations going on in your reaction flask. That day you will
be grateful to what I told you, because the satisfaction in chemistry can only be achieved trough comprehension and scientific approach - all the rest
is just trying to be kewl, and kewls either grow up (with permanent injuries or not) or just die.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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mbrown3391
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I did the boiling on a stove top burner with a wire mesh/ceramic divider between the flask and the coils, not a Bunsen burner. There was no open
flame.
Have you never had an accident in the lab?
And once again you point out grammatical errors, so i will do the same.
| Quote: | Originally posted by Nicodem
I bet you did not even use any boiling chips or else you would not experience the delights of a high boiling liquid superheating.
And accident was only while trying to concentrate your solution.
...But it is obviously from your posting style that you are simply lazy |
Hopefully this time you will do the mature thing, and not delete this post simply because i pointed out your hypocrisy.
[Edited on 31-8-2008 by mbrown3391]
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ScienceSquirrel
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I have had accidents in the lab, everybody does.
But most of my accidents were in the earlier part of my career when I was using aqueous copper sulphate and sodium carbonate etc while doing 'O' and
'A' level.
By the time I was using carbon monoxide under pressure I had got my 'newbie' accidents out of the way and had years of experience.
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mbrown3391
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A fair point. I do not pretend not to be a "newbie." However i do feel that with the correct precautions taken, it is more a matter of equipment than
experience in this case (i.e. magnetic stirrer, sand bath as you described. I did not take the correct precautions while boiling that ethanol because
of a false sense of security from all the other distillations i have done, and i now can can see the situations where experience is vital. I will put
a lot of thought into the decision to go through with this reaction.
On a different note, what are the possibilities of this reaction occurring at room temperature over, say, months?
[Edited on 31-8-2008 by mbrown3391]
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
On a different note, what are the possibilities of this reaction occurring at room temperature over, say, months?
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To be honest I think the chances are that Hell will freeze over first.
I reckon the sort of thing that will give you a reasonable rate of reaction is concentrated caustic alkali, potassium hydroxide for preference, in a
glycol / water solvent system at reflux temperature.
See my experimental post further up thread.
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mbrown3391
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I have to admit i didn't quite understand your notation: 90% potassium hydroxide. Does this mean 90% saturation? If not, how close was your solution
to the maximum amount of dissolved hydroxide?
[Edited on 31-8-2008 by mbrown3391]
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
I have to admit i didn't quite understand your notation: 90% potassium hydroxide. 90% by weight? 90% saturation? how close was your solution to the
maximum amount of dissolved hydroxide?
[Edited on 31-8-2008 by mbrown3391] |
That is a reference to the fact that potassium hydroxide is seldom purchased as a pure material. It is so hygroscopic that even when molten it still
contains some water.
The molten caustic is formed into small beads known as prills or rolled out into flakes.
Usually it is sold as containing anywhere between 70 and 90% potassium hydroxide, when making up solutions one allows for the water.
100mM of 100% potassium hydroxide would weigh 5.6g but my sample is ca 90+% so I use 6g. My resultant solution will be roughly 5M in terms of
concentration but I am not that bothered if it is say 4.8 or 5.2M as I am using it in large excess and if the experiment had worked I would have
calculated my yield on the basis of my limiting reactant which is DEET.
[Edited on 31-8-2008 by ScienceSquirrel]
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Nicodem
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| Quote: | Originally posted by mbrown3391
Have you never had an accident in the lab? |
Several times. Though luckily never anything serious. Excepts for a couple of minor burns&cuts, I never had any injury and I hope it will remain
like that till retirement. However, what you constantly ignore is that you are obviously autodestructive with your attitude and that makes it a
completely different situation. I do not go working in the lab disregarding what is going on during the reaction or reaction work up. Just think about
it. You don't use boiling chips and then you act surprised when the thing blows up in your face. Is that supposed to be a responsible attitude? It is
the same type of attitude as when I criticize your spelling and you don't do anything about it, yet act surprised and offended (and I’m not even a
native English speaker, so I dare not to think what your teachers might think of your spelling).
To reiterate what is wrong with your attitude: If you don't even use the shift key after you are being asked to do so, then how can you act surprised
if someone think you are lazy?
… or in other words: If you don't use boiling chips to prevent superheating, how can you act surprised when the flask contents blow out of the
flask?
All you have to do is change your attitude and you might become a good chemist, but until then you will only be continuously surprised as to why your
experiments blow up or just don't do anything at all.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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mbrown3391
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I am utterly dumbfounded at the way you continuously criticize my grammar and yet just as continuously make grammatical errors yourself.
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mbrown3391
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| Quote: | | My resultant solution will be roughly 5M in terms of concentration |
Can't the reaction be expected to proceed at least a little more quickly with a higher concentration of hydroxide? I cant calculate Molarity because i
dont know how NaOH displaces water, but a saturated solution is around 27 molal
[Edited on 31-8-2008 by mbrown3391]
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
I am utterly dumbfounded at the way you continuously criticize my grammar and yet just as continuously make grammatical errors yourself.
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To be fair, English is not Nicodem's first language while English is yours.
Nicodem had to learn English at the same time as he learnt chemistry as most journals etc are in English.
I learnt some German so I could read Beilstein etc but I would have been pretty stumped if all of Chemical Abstracts etc had been in German.
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
| Quote: | | My resultant solution will be roughly 5M in terms of concentration |
Can't the reaction be expected to proceed at least a little more quickly with a higher concentration of hydroxide? I cant calculate Molarity because i
dont know how NaOH displaces water, but a saturated solution is around 27 molal
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Increasing the molarity is an option but you have to consider that fact that you are using water and glycol as a solvent so the caustic will be less
soluble in that than pure water.
Also potassium hydroxide is more soluble in alcoholic liquors so it is preferred over sodium hydroxide eg for biodiesel manufacture.
You also have to factor in other considerations. 27M sodium hydroxide would be more like a thick oil than a normal solution and this may cause
complications with stirring etc.
Experimental conditions tend to be a trade off.
One of the advantages of having read a lot of experimental and done a lot of experiments is that you can devise a reasonable protocol for a new
reaction from your knowledge of the 'prior art'.
[Edited on 31-8-2008 by ScienceSquirrel]
[Edited on 31-8-2008 by ScienceSquirrel]
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mbrown3391
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And his fluency is impressive. However, hypocrisy is hypocrisy.
Edit: Also, most of his errors are clearly typos and not misunderstandings of the language.
[Edited on 31-8-2008 by mbrown3391]
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Nicodem
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Stop being pathetic!
If you don’t have anything rational to say about my criticism, then just don’t say anything. Post only chemistry related things, like literature
examples and references which you still had not provided. It is unbelievable that you managed to push this thread to its 6th page and yet did not
bother to provide a single example of tertiary benzamide hydrolysis. It appears to me you did not even bother to check the most basic sources like
Vogel’s or similar.
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mbrown3391
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Unless it is available in some OTC product, I don't see why I would have posted an example of it. This is clearly about synthesizing DEA without
ordering chemicals, or else I would just order the DEA.
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Klute
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Oh my.... He is not asking for the brand aname of whatever product, but a litterature reference, a procedure detailing the recation you
want to perform. ANy example of someone trying this out, to show htat you have done soem minimal research on your own, and not just arrived empty
handed, waiting to be spoon-fed.
Agin, I would really recommend waiting some more before trying anything of this sort, if you don't knwo what a reference is...
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
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mbrown3391
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Ok i see, DEET is a tertiary benzamide. Sorry. But the post was confusing. I did post an example, i did not post a reference (there may not be one).
And Vogel's contains no mention of DEA synth, only dimethylamine synth.
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mbrown3391
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Seeing as the deet method has not seemed to work for science squirrel, i may try the Ethanal method i beleive someone mentioned earlier. This would be
comparable to the dimethylamine synth found in vogel's
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mbrown3391
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This is speculation:
If
2 CH2O + NH4Cl --> [CH3NHCH3]HCl + O2
Then
2 CH3CHO + NH4Cl --> [CH3CH2NHCH2CH3]HCl + O2
Vogel's says the first reaction takes around 5 hours at around 115 degrees C, so i assume the second reaction would be similar.
Does this seem more feasible? It would certainly be less expensive.
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Klute
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And where do you get your acetaldehdye?
I fyou can buy acetaldehyde, you can surely buy Et2NH... Making acetaldehdye without K2Cr2O7 isn't really trivial.
[Edited on 1-9-2008 by Klute]
\"You can battle with a demon, you can embrace a demon; what the hell can you do with a fucking spiritual computer?\"
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mbrown3391
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Vogel's describes synthesis of acetyldehyde from paraformaldehyde and sulfuric acid alone. I once accidentally made a considerable amount of
acetyldehyde from conc. sulfuric acid, 12% h2o2 and ethanol at low temperatures
CH3CH2OH + H2O2 --> CH3CHO + 2 H2O
[Edited on 1-9-2008 by mbrown3391]
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
This is speculation:
If
2 CH2O + NH4Cl --> [CH3NHCH3]HCl + O2
Then
2 CH3CHO + NH4Cl --> [CH3CH2NHCH2CH3]HCl + O2
Vogel's says the first reaction takes around 5 hours at around 115 degrees C, so i assume the second reaction would be similar.
Does this seem more feasible? It would certainly be less expensive. |
Methanal ( formaldehyde ) reacts with ammonia to form dimethylamine but not in any way like that.
Ethanal ( acetaldehyde ) reacts with ammonia but not to form diethylamine.
Back to the books!
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mbrown3391
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| Quote: | | Ethanal ( acetaldehyde ) reacts with ammonia but not to form diethylamine. |
Any idea what it does form?
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ScienceSquirrel
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| Quote: | Originally posted by mbrown3391
Any idea what it does form? |
Why don't you go and find out for yourself 
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