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entropy51
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| Quote: | | There is a condenser that is made just for reflux operations and it is very similar to a Graham type condenser except the cooling fluid flows through
the coil instead of the jacket |
Sorry Dude, but that condenser is often used to distill solvents like ether,
in which case it is not refluxing, and thus not "just for reflux". It is sometimes called a "reversed Graham condenser".
It sounds as if you are using it as a fractionating column? Or what? It would be nice if you were able to describe what you are doing in a
comprehensible fashion. If you could do that you might get a useful answer, which you have not so far, have you? GIGO.
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hissingnoise
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Deta, fractional distillation works on concentrations above ~68% but this is the azeotrope conc. and it distills unchanged. . .
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DetaDude
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A "reversed Graham condenser" is not what Wilmad Labglass calls it.
And while we're at it why are we picking rat turds out of rice on a subject that I started this thread with. Read the first post as my intentions were
to help some of our less learned citizen newbie chemists get a grasp on some of the various methods used to concentrate nitric acid, and share some of
our experiments / experience. I did not wish to start a "I'm better than you" contest.
I just wanted to put some things in simple laymen terms,
..
Genius creates many a great works............Labor alone finishes them!
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hissingnoise
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Anyway, DetaDude, you're lucky you can get 70% HNO3 to concentrate from H2SO4---most of us have to go the nitrate route for our strong acid,
spending weekends washing KHSO4 out of flasks. . .
And I like the idea of not using up H2SO4 every time I want HNO3!
Still. . .
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entropy51
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Sooo, are you going to tell us what you mean by
this? If you're using your relux condenser as a column, no you won't separate an azeotrope with a column.
[Edited on 19-12-2009 by entropy51]
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hissingnoise
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Gnnnge! What happened the Dulcolax reference?
It ain't something I'd need and even if I did, I'd 'pass' on it---prune juice for me if I needed anything.
But to the topic---to me, the HNO3 azeotrope is one of nature's cruelest cuts!
Why the fuck can't it be like ethanol?
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User
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Sure true!
Come on it really doesn't have to be that hard at all.
Why not buy 10 litre's of SA(battery) and a couple a kilo's KNO3
And a large flask (5 litre).
Take the weekend off !
Omg yes it is terrible 
What a fine day for chemistry this is.
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DetaDude
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entropy51
Had you read my original post you would know by now that I am not distilling an azeotrope, which would be straight 70% HNO3 and that is why I mix
H2SO4 with the nitric so when I run the distillation I'm dealing with pretty clean HNO3 vapor.
Does anyone but this guy understand what I'm saying , or can anyone else figure it out?
I believe hissingnoise has it figured out.
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DJF90
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You're making very little sense DetaDude. If you're distilling something close to WFNA (as I suspect, under vacuum and using equal quantities of
azeotropic nitric acid and conc. sulfuric acid) then whats the point in adding in a reflux condenser? To get anhydrous HNO3 you can distil the WFNA
with another equal volume of conc. sulfuric... or something like that (I cannot remember the exact details).
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DetaDude
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DJF90
Thanks for the input. Just to clear the air I DO NOT use any reflux setup for the distillation of HNO3.
I do use such a setup when making booze, and have been told by others that they have used such a setup to distill HNO3 and since I've never heard of
any results on this type of arraingment, I was hoping someone may of had some knowledge about this topic to share it with others.
Genius creates many a great works............Labor alone finishes them!
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Magpie
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Deta Dude, does it strike you as being a little odd that all these experienced (hands-on) chemists can't figure out why or how you would use a reflux
column for making nitric acid?
Why don't you provide us with a picture or a sketch.
[Edited on 20-12-2009 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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DetaDude
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magpie
What I find odd is that people on this and other threads start making comments without analyzing what the original/initial post was about.
Not all of the people on this board are graduate chemists, but merely average joe's/jane's with an interest in chemistry etc. so I for one would not
be able to identify a "hands on chemist" if they bit me on the ass.
That said, on none of my posts have I made any claims to distilling nitric acid using a "reflux condenser", what I did say was that I've heard it
reported elsewhere that this type of setup has been used. All I was asking is has anyone ever done this ,and if so how and what was the outcome.
As to a picture/diagram I'd be glad to do that , however I have absolutely no knowledge of how to perform the task of getting it from my desk into
this computer and onto the discussion board.
I do use a packed column and reflux when I distill whiskey .
Genius creates many a great works............Labor alone finishes them!
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crazyboy
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Quote: Originally posted by DetaDude  | What I find odd is that people on this and other threads start making comments without analyzing what the original/initial post was about.
Not all of the people on this board are graduate chemists, but merely average joe's/jane's with an interest in chemistry etc. so I for one would not
be able to identify a "hands on chemist" if they bit me on the ass.
That said, on none of my posts have I made any claims to distilling nitric acid using a "reflux condenser", what I did say was that I've heard it
reported elsewhere that this type of setup has been used. All I was asking is has anyone ever done this ,and if so how and what was the outcome.
As to a picture/diagram I'd be glad to do that , however I have absolutely no knowledge of how to perform the task of getting it from my desk into
this computer and onto the discussion board.
I do use a packed column and reflux when I distill whiskey . |
Almost all of the regular members here are average people who experiment at home with chemistry, sure there are some that have made it a profesion but
they also experiment at home or they wouldn't have much reason to be here at all.
As for none of your posts mentioning distillation with a reflux condesder, how about the one one the first page of this thread in which you say:
| Quote: |
Has anyone tried concentrating nitric with a reflux set up, if so how about a little feed back on how it was done, and the outcome, equipment used,
was vacuum involved, did you also use a column, etc. |
Hmmmm reflux setup very close to what you just denied saying.
I suspect you mean fractional distillation which would require a column, this is possible however if you start with dry KNO3 and H2SO4 there won't be
very much water in your product and any that is left could be eliminated by distilling your product mixed with additional sulfuric acid under a vacuum
protected by a water trap made basic with NaOH.
A fractionating column isn't really helpful in this case because the only compounds present are HNO3, H2O and sulfuric acid (sulfuric acid won't
distill easily.) Also nitric acid decomposes in the presence of heat and light which is why a fractionating column which returns vapor to the reaction
flask would be counter productive.
Why are you so intent on getting nitric acid of such high concentrations anyway? nitric acid above concentrations of 90% is extremely dangerous and a
nuisance to work with, I have some in my freezer in a Ziploc bag right now and even after frost forms on the outside of the bottle it still vents
plumes of caustic vapors
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Magpie
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| Quote: Originally posted by DetaDude |
...what I did say was that I've heard it reported elsewhere that this type of setup has been used. All I was asking is has anyone ever done this ,and
if so how and what was the outcome.
As to a picture/diagram I'd be glad to do that , however I have absolutely no knowledge of how to perform the task of getting it from my desk into
this computer and onto the discussion board.
I do use a packed column and reflux when I distill whiskey . |
>I tend to agree with crazyboy that those reports you heard of others using a reflux column were made by people who were using a fractionating
column. Refluxing is inherent in a fractionating column's operation and maybe they were just not careful in their speech.
>Using computer technology by AOOF's can be a challenge! I should know. Do you have "paint" on your computer? (Start>All
Programs>Accessories>Paint) If so, I recommend you learn to use it - it's fun. Get your kids or grandkids to show you how.
>For alcohol/water separation I'd say a fractionating column is essential. It's all got to do with relative volatility. Alcohol/water is a much
tougher situation than water/azeotropic HNO3, especially if you start out with no extra water in the pot. You don't have that choice with fermented
alcohol.
So I suspect your last sentence quoted above is inaccurate in the same way. Just say that you use a fractionating column. Mentioning reflux here
just confuses the chemists. 
Edit: I just thought of one other possibility: In industrial applications when using a fractionating column part of the condensate from the
condenser is routed back to the fractionating column and added in as "reflux." This stream is usually added at the top of the fractionating column.
It is used to obtain a condensed vapor of very high purity. Is this what you are doing with your whiskey?
[Edited on 20-12-2009 by Magpie]
[Edited on 20-12-2009 by Magpie]
The single most important condition for a successful synthesis is good mixing - Nicodem
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hissingnoise
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DetaDude said at the outset that he wasn't an experienced chemist, but now, what has transpired sounds like galloping, chemical 'political
correctness'.
Why some people are making a big deal out of it is beyond me?
Chill out. . .
[Edited on 20-12-2009 by hissingnoise]
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entropy51
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| Quote: | Why some people are making a big deal out of it is beyond me?
Chill out. . . |
As a charter member, you know that AOOOF are permitted a little grumpiness now and then...
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hissingnoise
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Ooof!. . .Touché!
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DetaDude
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crazy boy / magpie
Thanks for the input, your comments are well received. Not being a pro in the chemistry field or for that matter college level schooled in the
subject, I will say I'm sorry for not making myself clearer, or using the proper or correct wording.
From the start of this thread I made it clear that I am not a pro grade chemist. All of my chemistry has been via the college of hard knowledge, a
book here and there and hands on experiments.
Speaking of hands, I still have both of them and all ten of the original digits, given the fact that I was for some thirty years a journeyman
machinist, and played around in the pyrotechnics field since age 11, at least I've been very cautious .
When I started this thread, I thought that I was pretty clear on my experience and that the thread was aimed at the novice people, and that I wished
to keep it simple and "plain vanilla" I was hoping that the more astute chemists among the group would be able to understand what was being posted
even if it seemed a little awkward or incorrect.
I'm sorry that I was somewhat short sighted about the ability of a very small percentage of those that post here, to use a bit of common sense.
I do want to say a sincere thank you for constructive contributions.
Hissingnoise.........Thank You
P.S. I have several grandkids that are computer geeks, but I live in a very rural area and they don't get out here very often.
Genius creates many a great works............Labor alone finishes them!
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User
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Another approach that somehow seems very uncommon is the use af a dessicant.
For example P2O5 (which was proposed by someone i know from another forum) is a very suitable dehydrant.
He actually used it an proofed that it does work.
By adding enough to take away all the water in an azeotropic mixture one can obtain very close to 100% HNO3.
I know this is a very difficult chemical to obtain.
Funny how there are almost no references about this.
Another way i thought of is to use a XNO3 salt (preferably a heavier metal) that is clear of water.
By adding this to the nitric acid it could simply adsorb all remaining water.
Another issue here is that it isnt very easy to make these salt in anhydrous state due to their tendency to decompose instead of dehydrate.
An advantage of using XNO3 salts is that they don't react with nitric acid.
It could be quite straightforward and quick.
What a fine day for chemistry this is.
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DJF90
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User: P2O5 is very well known for its use as a dessicant, and I would not hesitate to say it would most certainly increase the concentration of
azeotropic nitric acid by reacting with the water present. However I disagree with "one can obtain very close to 100% HNO3". You CAN obtain 100%, and
with even more P2O5, you can dehydrate the 100% nitric acid even further to its acid anhydride, dinitrogen pentoxide (N2O5), much like you can make
SO3 from H2SO4 and P2O5.
Like you say, P2O5 is a very difficult chemical to obtain for most of us, so it makes sense to use conc sulfuric acid instead. Mixing azeotropic HNO3
with an equal volume of conc. sulfuric acid and distilling will get you to 90%+ HNO3, which can then be mixed again with an equal volume of conc.
sulfuric acid and distilling to get essentially 100% HNO3. Then if you want to make N2O5, you waste much less P2O5 on absorbing water that can be
removed from azeotropic HNO3 by non chemical means.
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User
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Sorry with uncommon i meant: using it to dehydrate HNO3
Or better: using P2O5 to dehydrate NA isn't mentioned very often.
What a fine day for chemistry this is.
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DetaDude
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DJF90 / User
I've heard of using P2O5 to pull the H2O from HNO3 but have never seen the process explained anywhere.
Would one of you or poss. another member be willing to write up a procedure for doing this, including ammounts, times, temps., etc.
Thanks in advance
,
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gnitseretni
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| Quote: Originally posted by User | Another way i thought of is to use a XNO3 salt (preferably a heavier metal) that is clear of water.
By adding this to the nitric acid it could simply adsorb all remaining water.
|
Are you saying that, instead of distilling twice to get a higher concentration, I can just add some NH4NO3 to my say 90% HNO3, filter it, and end up
with 95% or even better depending on how dry my AN is?
That sure sounds better than distilling twice!
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crazyboy
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Sorry, I don't see using phosphorus pentoxide to desiccate HNO3 as practical, from an economic standpoint or a chemistry one. As Wikipedia says:
"The desiccating power of P4O10 is strong enough to convert many mineral acids to their anhydrides. Examples: HNO3 is converted to N2O5; H2SO4 is
converted to SO3; HClO4 is converted to Cl2O7."
So where have you heard of P4O10 being used to desiccate HNO3 DetaDude?
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User
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| Quote: |
[Quote] Originally posted by User
Another way i thought of is to use a XNO3 salt (preferably a heavier metal) that is clear of water.
By adding this to the nitric acid it could simply adsorb all remaining water.
Are you saying that, instead of distilling twice to get a higher concentration, I can just add some NH4NO3 to my say 90% HNO3, filter it, and end up
with 95% or even better depending on how dry my AN is?
That sure sounds better than distilling twice!
|
No thats not really what i was saying.
If course it has to be a salt that 'captures' water, as far as i know AN does not have to ability to trap H20 in its structure.
I meant a substance that binds water to itself.
Does anyone know a method for preparing for example copper(||)nitrate in anhydrous form?
Simply heating it just decomposes the material.
[Edited on 20-12-2009 by User]
[Edited on 20-12-2009 by User]
What a fine day for chemistry this is.
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