| Pages:
1
2
3
4
5 |
woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
I don't have figures for solubility of NH4ClO4, but as far as I remember, this stuff is MUCH more soluble than KClO4. So, in your solution of KClO4
and NH4Cl, I think that you just again get crystals of KClO4.
Once you have KClO4, it is very hard to make any other perchlorate of it. KClO4 is one of the least soluble salts of perchlorate. For this reason I
have purchased NaClO4 as my primary perchlorate salt, that leaves me the possibility to make any other perchlorate salt. Finally, when the perchlorate
is not used anymore in aqueous solution, then I add KCl just to precipitate the waste perchlorate and recrystallizing the KClO4 gives my perchlorate a
second life, but this time not anymore for aqueous chemistry.
|
|
|
YT2095
International Hazard
Posts: 1091
Registered: 31-5-2003
Location: Just left of Europe and down a bit.
Member Is Offline
Mood: within Nominal Parameters
|
|
so the the Cl won`t pull the K then?
leaving my ammonium perchlorate, as it would if it was a Sodium salt.
Damn!
thnx anyway 
\"In a world full of wonders mankind has managed to invent boredom\" - Death
Twinkies don\'t have a shelf life. They have a half-life! -Caine (a friend of mine)
|
|
|
Engager
Hazard to Others
Posts: 295
Registered: 8-1-2006
Location: Moscow, Russia
Member Is Offline
Mood: Lagrangian
|
|
Solubility in g/100ml - y axis, temperature in celsius - x axis. For NH4ClO4:
[img]http://www.ruspyro.net/Chlorates/NH4ClO4(Sol).bmp[/img]
For KClO4:
[img]http://www.ruspyro.net/Chlorates/KClO4(Sol).bmp[/img]
[Edited on 27-8-2006 by Engager]
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
Guys, what will happen if one attempts to make HClO4 out of KClO4 and H2SO4 distillation
suppose, we boil KClO4 and H2SO4(diluted of course) in order to make some K2SO4 and HClO4, then we filter all the solids(K2SO4, and unreacted KClO4)
and then distill WITHOUT vacum at 203 degrees.... what will happen?
will the HClO4 decopmose? will the anhydrous acid come out .. what will happen?
BTW I can filter only with glass filters right?
|
|
|
Fleaker
International Hazard
Posts: 1252
Registered: 19-6-2005
Member Is Offline
Mood: nucleophilic
|
|
Yes only glass, keep away from any organics whether you're dealing with dilute or concentrated. It is important to note that while the conc. (90% +)
acid can cause an instant explosion, dilute solutions carry the risk of forming unstable compounds that make explode later on (sometimes years) due to
friction, shock, or heat.
I would not attempt a distillation at its boiling point...that is asking for an explosion. If you're after the anhydrous acid, I'm sure that Brauer
has a safe, effective Preparation for it. If you don't have Brauer's excellent text, it is available in the forum library.
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
|
|
|
hashashan
Hazard to Others
Posts: 255
Registered: 10-10-2006
Member Is Offline
Mood: No Mood
|
|
Dude, i dont need the anhydrous ... I am after the azetropic acid.
I was told that It is possible to distill it at 203 without any problems .. I just dont understand why everyone does that under vacum
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
| Quote: | Originally posted by chloric1
Several years ago I made about 100 to 150ml of Aqua regia and then added ammonium perchlorate. You get a soup of nitrous acid, oxides, and chlorine.
The solution is black cherry colored and I let it set undesturbed for the night to eliminate risk for explosions. After the solution is clear or off
yellow, it is safe to distill off the excess nitrous-hydrochloric-chlorine solution and the 72 % constant boiling acid is in the flask. The file I am
attaching should elighten you all to the theories on the mechanism for this reaction. Mind you, my explorations where 7 years before I obtained this
file so the mounts of nitric and hydrochloric acid I used where quite excessive. This proceedure would definately be a cheaper as far as reagents are
concerned. |
I've used a method similar to this described in Gmelin. They say the yield is 99.7 to 99.8%. I adjusted it to use subconcentrated HNO3 (Gmelin says to
use 68 to 70% HNO3) and scaled it down by 10 times:
50 g NH4ClO4 is put into 60 mL H2O and then mixed. Then added 51.5 g 54% HNO3 and mixed in a 400 mL beaker. These are then heated to boiling on a hot
plate and eventually all of the AP dissolved.
Then rapidly a significant portion of 12.4 g 31% HCl in 38 mL H2O is added while the mixture is still boiling, and then later portionwise is the rest
added.
After a bit of boiling there was a significant Cl2 odor (done outside), but I didn't see any nitrogen oxides or strong coloring in the solution. Then
later it started boiling less, and then a white powder began precipitating here is where heating was stopped. A lot more ammonium salts deposit as the
solution cools. Here I thought something must be wrong.
So, the liquid was siphoned off with a few crystals coming over in the process. Now after boiling this liquid in the beaker on a hot plate, an
extremely massive amount of very thick, odorless white fumes began to show (HClO4) and heating stopped here. Then after sitting several hours the
liquid was still cloudy from the solids and the volume is just under 30 mL. Letting this oily liquid stand overnight, there was finally separation
possible and it was clear and colorless and could be siphoned off, where the density was about 1.68 g/cc (71.5%). Likley the formation of solids may
have been avoided by use of higher strength acid and containing nitrogen oxides.
Gmelin also mentions this method and says it doesn't work with KClO4, and gives a low yield of 80% using Ba(ClO4)2, where NaClO4 gives about 95%
yield. Other formation and preparations covered are: KClO4 and H2SiF6, aqueous HClO3, Cl2 and O2 or O3, Cl2 water, O3 and hypochlorite, oxidation of
chlorate, and formation from ClO2, distillation of KClO4 with H2SO4, and vacuum distillation of the same, and distillation of HClO3.
| Quote: | Originally posted by hashashan
Dude, i dont need the anhydrous ... I am after the azetropic acid.
I was told that It is possible to distill it at 203 without any problems .. I just dont understand why everyone does that under vacum
|
72% HClO4 decomposes partly when distilled in atmospheric pressure, so it should be distilled under reduced pressure (the decomposition is about 10%
at 760 mm Hg, so the highest should be 200 mm Hg according to Gmelin, preferably at 15 to 20 mm, but even this acid has a weak odor of chlorine
oxides).
[Edited on 22-8-2008 by Schockwave]
|
|
|
dann2
International Hazard
Posts: 1523
Registered: 31-1-2007
Member Is Offline
Mood: No Mood
|
|
Hello,
Since there is no Ammonium Perchlorae thread I reckoned I would post this here.
Can Nafion (reg. trade mark) be had by the common Joe (or indeed the common Mary if she was so inclined!).
Dann2
Attachment: amm_perk.pdf (635kB)
This file has been downloaded 1997 times
|
|
|
dann2
International Hazard
Posts: 1523
Registered: 31-1-2007
Member Is Offline
Mood: No Mood
|
|
Hi,
Came accross this while scouring the net (as one does) and decided to plonk it up here. There are some rather 'Heath Robinson' looking apparati in it.
Have a good bedtime read!!
Dann2
Attachment: Kalichevsky_va_1924.pdf (1.6MB)
This file has been downloaded 739 times
|
|
|
watson.fawkes
International Hazard
Posts: 2793
Registered: 16-8-2008
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by dann2
Can Nafion (reg. trade mark) be had by the common Joe (or indeed the common Mary if she was so inclined!). |
Yeah, but it's pricey. I seem to remember that there's a project using that membrane in Fuel Cell Projects for the Evil
Genius. Here's an internet seller of the membrane. A 15 cm square piece goes for 60 - 80 USD, depending on thickness. But there are more materials problems than
just that.
| Quote: | From A novel electrochemical process for the production of ammonium perchlorate
The 20 amp, cathode-membrane sandwich perchloric acid cell with Hastelloy cathode and platinum coated niobium anode was operated at current
densitities ranging up to 10 kA m<sup>-2</sup>. |
Got a small-scale source for Hastelloy or
platinum-coated niobium? I suspect that anode is even more expensive.
|
|
|
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
McMaster sells hastelloy hardware, but no sheet, surprisingly. Washers up to 2" o.d.
Tim
|
|
|
watson.fawkes
International Hazard
Posts: 2793
Registered: 16-8-2008
Member Is Offline
Mood: No Mood
|
|
Here's the Haynes International page on their corrosion resistant alloys. It's the C series that's relevant to oxidizing acids. C-2000 is probably the right one to use, as its specifically
designed for chloride resistance.
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
See section 23 of Perrys Chemical Engineers Handbook. It has a good tabulation of corrosion-resistant alloys and other materials and their
compositions, and their specific corrosion resistances or otherwise. From these tables, of the Hastelloys, only Hastelloy B, which is about 61% Ni,
28% Mo, 5% Fe, with small amounts of Mn and Si, seems to be fully satisfactory against chloride; but it is "not recommended" for use with nitric acid
(which may also be the case with chloric and perchloric acids which are similarly oxidizing acids, but the data for them is not given). However, the
other Hastelloys (A and C), Ni-o-nel, and 14% Si iron are quite satisfactory against oxidizing acids.
|
|
|
chloric1
International Hazard
Posts: 1070
Registered: 8-10-2003
Location: GroupVII of the periodic table
Member Is Offline
Mood: Stoichiometrically Balanced
|
|
| Quote: | Originally posted by Formatik
| Quote: | Originally posted by chloric1
Several years ago I made about 100 to 150ml of Aqua regia and then added ammonium perchlorate. You get a soup of nitrous acid, oxides, and chlorine.
The solution is black cherry colored and I let it set undesturbed for the night to eliminate risk for explosions. After the solution is clear or off
yellow, it is safe to distill off the excess nitrous-hydrochloric-chlorine solution and the 72 % constant boiling acid is in the flask. The file I am
attaching should elighten you all to the theories on the mechanism for this reaction. Mind you, my explorations where 7 years before I obtained this
file so the mounts of nitric and hydrochloric acid I used where quite excessive. This proceedure would definately be a cheaper as far as reagents are
concerned. |
I've used a method similar to this described in Gmelin. They say the yield is 99.7 to 99.8%. I adjusted it to use subconcentrated HNO3 (Gmelin says to
use 68 to 70% HNO3) and scaled it down by 10 times:
50 g NH4ClO4 is put into 60 mL H2O and then mixed. Then added 51.5 g 54% HNO3 and mixed in a 400 mL beaker. These are then heated to boiling on a hot
plate and eventually all of the AP dissolved.
Then rapidly a significant portion of 12.4 g 31% HCl in 38 mL H2O is added while the mixture is still boiling, and then later portionwise is the rest
added.
After a bit of boiling there was a significant Cl2 odor (done outside), but I didn't see any nitrogen oxides or strong coloring in the solution. Then
later it started boiling less, and then a white powder began precipitating here is where heating was stopped. A lot more ammonium salts deposit as the
solution cools. Here I thought something must be wrong.
So, the liquid was siphoned off with a few crystals coming over in the process. Now after boiling this liquid in the beaker on a hot plate, an
extremely massive amount of very thick, odorless white fumes began to show (HClO4) and heating stopped here. Then after sitting several hours the
liquid was still cloudy from the solids and the volume is just under 30 mL. Letting this oily liquid stand overnight, there was finally separation
possible and it was clear and colorless and could be siphoned off, where the density was about 1.68 g/cc (71.5%). Likley the formation of solids may
have been avoided by use of higher strength acid and containing nitrogen oxides.
Gmelin also mentions this method and says it doesn't work with KClO4, and gives a low yield of 80% using Ba(ClO4)2, where NaClO4 gives about 95%
yield. Other formation and preparations covered are: KClO4 and H2SiF6, aqueous HClO3, Cl2 and O2 or O3, Cl2 water, O3 and hypochlorite, oxidation of
chlorate, and formation from ClO2, distillation of KClO4 with H2SO4, and vacuum distillation of the same, and distillation of HClO3.
| Quote: | Originally posted by hashashan
Dude, i dont need the anhydrous ... I am after the azetropic acid.
I was told that It is possible to distill it at 203 without any problems .. I just dont understand why everyone does that under vacum
|
72% HClO4 decomposes partly when distilled in atmospheric pressure, so it should be distilled under reduced pressure (the decomposition is about 10%
at 760 mm Hg, so the highest should be 200 mm Hg according to Gmelin, preferably at 15 to 20 mm, but even this acid has a weak odor of chlorine
oxides).
[Edited on 22-8-2008 by Schockwave] |
Well I had solid ammonium perchlorate in the beaker, added 68%, then 31.45% HCl. The solution was dark colored because the nascent chlorine formed
from the HCl started attacking the ammonium ion as well as forming NOCl and NOx. When the ammonium perchlorate crystals disappeared the next day, if
figured ammonium was destroyed leaving nitrogen oxides, chlorine, excess HCl, hydronium and perchlorate ions. In fact I had this as I boiled said
mixture until excessing smoking stopped and I had a viscous clear excessively caustic odorless liquid. I dropped some on concrete and reaction
commensed only slightly faster than 98% sulfuric acid on concrete. Some more detailed analysis would have been better here, but I know this reaction
works.
Fellow molecular manipulator
|
|
|
S.C. Wack
bibliomaster
Posts: 2419
Registered: 7-5-2004
Location: Cornworld, Central USA
Member Is Offline
Mood: Enhanced
|
|
| Quote: | Originally posted by Formatik
I've used a method similar to this described in Gmelin.
...
Gmelin also mentions this method and says it doesn't work with KClO4, and gives a low yield of 80% using Ba(ClO4)2, where NaClO4 gives about 95%
yield. |
These references might be pretty easy to obtain for those interested in reading them, so it would be nice to know what Gmelin says they are. I'm
guessing
http://dx.doi.org/10.1021/ja02212a006
and
http://dx.doi.org/10.1021/ja01919a004
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
| Quote: | Originally posted by S.C. Wack
| Quote: | Originally posted by Formatik
I've used a method similar to this described in Gmelin.
...
Gmelin also mentions this method and says it doesn't work with KClO4, and gives a low yield of 80% using Ba(ClO4)2, where NaClO4 gives about 95%
yield. |
These references might be pretty easy to obtain for those interested in reading them, so it would be nice to know what Gmelin says they are. I'm
guessing
http://dx.doi.org/10.1021/ja02212a006
and
http://dx.doi.org/10.1021/ja01919a004 |
The NaClO4 method cited is that from Kreider in: Z. anorg. Ch. 9 [1895] 342; but also used by others in Z. anorg. Ch. 66 [1910] 244 and JACS 32 [1910]
4. Non-applicability of KClO4 and low yield from Ba(ClO4)2 is: JACS 32 [1910] 66 and Ch. Ztg. 34 [1910] 1317.
|
|
|
watson.fawkes
International Hazard
Posts: 2793
Registered: 16-8-2008
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by JohnWW
of the Hastelloys, only Hastelloy B, [...] fully satisfactory against chloride; but it is "not recommended" for use with nitric acid (which may also
be the case with chloric and perchloric acids which are similarly oxidizing acids, but the data for them is not given). |
The Haynes site states clearly that the Hastelloy B series is resistant against non-oxidizing acids and that the Hastelloy C series
against oxidizing acids. So I did just say "chloride", when I should have said "chloride with oxidizing acids".
Having said all this, the Haynes site has a link on their home page to get metallurgical advice. Anybody consider actually doing this should just
contact them rather than trusting me.
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
| Quote: | Originally posted by jpsmith123
Just in case anyone's interested, here's a patent I found regarding the production of HClO4 by electrolytic oxidation of HCl.
Regards,
Joe |
This would be a nice way to prepare HClO4, if one didn't have to use highly dilute solutions. Gmelin also talks about it in Cl 6, 218: electrolysis of
a dilute (0.1 n-) aq. solution of HCl using an anode of pure Pt, and a cathode of copper, 50% of the used HCl converts to HClO4. The larger part which
is not converted escapes as Cl2. With increasing concentration of the HCl the conversion of HCl -> HClO4 reduces drastically, using a 0.5
n-solution, only 10% is oxidized to HClO4, where the remaining HCl (in n-HCl almost completely) escapes as Cl2. However, the content of HClO3
increases with increasing HCl.
Might as well just electrolyse a -Cl or -ClO3 salt for the perchlorate salt and then use that to form the acid.
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
Another preparation could be through oxalic acid. Using a calcium chlorate solution and oxalic acid solution to form HClO3. The calcium oxalate
precipitate then removed. Calcium oxalate is around as insoluble as BaSO4. But oxalates are already more obtainable than barium salts. Lieb. Ann. 57
[1846] 138 details a method using solutions of NaClO3 and saturated oxalic acid frozen with a freezing mixture to precipitate most sodium oxalate.
Though the acid made there is impure. Then decomposing the HClO3.
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Quote: Originally posted by Formatik  | | Another preparation could be through oxalic acid. Using a calcium chlorate solution and oxalic acid solution to form HClO3. The calcium oxalate
precipitate then removed. Calcium oxalate is around as insoluble as BaSO4. But oxalates are already more obtainable than barium salts. Lieb. Ann. 57
[1846] 138 details a method using solutions of NaClO3 and saturated oxalic acid frozen with a freezing mixture to precipitate most sodium oxalate.
Though the acid made there is impure. Then decomposing the HClO3. |
No crossed oxydoredox between strongly opxydant HOClO2 and reducer HO2C-CO2H?
In books they propose exces HCl (30-35%) to admix with NaClO3...
So the maximum concentration of HClO3 remains in the range where it is stable (<30%), NaCl precipitates out because it is less soluble than NaClO3
or NaClO4...then boiling this down produces the desired NaClO4/HClO4...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
I don't think they react since no mention was made of it, but possibly on boiling or slowly on prolonged standing. Oxalic acid seems to be fairly
resistant to some oxidizing acids (recall its simple preparation out of sugar, starch, etc. and boiling aq. HNO3 with evolution of copious nitrogen
oxides until they cease).
| Quote: | In books they propose exces HCl (30-35%) to admix with NaClO3...
So the maximum concentration of HClO3 remains in the range where it is stable (<30%), NaCl precipitates out because it is less soluble than NaClO3
or NaClO4...then boiling this down produces the desired NaClO4/HClO4...
|
That won't work. HClO3 reacts with HCl to form ClO2, Cl2. With more HCl you get more Cl2. Cl2 is favored with more acid and higher temperature. You
will be basically left with NaCl after everything has boiled away.
Also note that boiling NaClO4 with conc. HCl (without filtering first the NaCl) will leave you with sodium perchlorate as the HCl as boiled off since
boiling chlorides with aq. HClO4 leaves behind the perchlorate salt. But as discussed above, there is process starting from NaClO4 (either solid or
aqueous) and conc. HCl to get the HClO4 in very high yield.
|
|
|
chief
National Hazard
Posts: 630
Registered: 19-7-2007
Member Is Offline
Mood: No Mood
|
|
What about Ba(ClO4)2 with H2SO4 ? This would ppt. very (completely) unsoluble BaSO4 and leave only HClO4 in the liquid phase, possible to be filtered
through glasswool. Quite a simple one, is it not ?
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
| Quote: Originally posted by chief | | What about Ba(ClO4)2 with H2SO4 ? This would ppt. very (completely) unsoluble BaSO4 and leave only HClO4 in the liquid phase, possible to be filtered
through glasswool. Quite a simple one, is it not ? |
More obtainable HCl will work as mentioned above, though there the yield is lower than if using NaClO4. Barium perchlorate is very soluble and it will
work with H2SO4.
|
|
|
chief
National Hazard
Posts: 630
Registered: 19-7-2007
Member Is Offline
Mood: No Mood
|
|
But HCl then will yield BaCl2 ; H2SO4 on the contrary will yield _insoluble_ BaSO4, and the liquid phase will be clean HClO4 (as clean as weighted in,
thereby with trace-amounts of the excess-reagent, either H2SO4 or Ba(ClO4)2 )
|
|
|
Formatik
National Hazard
Posts: 927
Registered: 25-3-2008
Member Is Offline
Mood: equilibrium
|
|
| Quote: Originally posted by Formatik | | ... Another preparation could be through oxalic acid. Using a calcium chlorate solution and oxalic acid solution to form HClO3. The calcium oxalate
precipitate then removed. ... |
I've done a probe experiment with a small amount, and this works. But I didn't get a smooth decomposition of HClO3 on boiling, either because of
impurities in the chlorate or unstoichiometry. I took some aq. Ca(ClO3)2 (which was impure with a bit CaCl2) and mixed it with a clear conc. aq.
oxalic acid solution. I was relying on a precipitate for stoichiometry, but it didn't appear right after mixing. So I let it sit in the cold, in dark
area for several hours (longer than necessary actually, about 2 days) in a 50mL flask, lightly stoppered (the rubber cork was wrapped in PE plastic to
prevent potential violent interaction with ClO2).
Later there was a fine white precipitate and the solution was now pale yellow. The solution had now the smell of ClO2, and much more so than Cl2. And
after filtering, the white precipitate remained insoluble in an excess of water. After some research I also found out Ca(ClO3)2 can be obtained pure
from CaCl2 or Ca(ClO2)2 by using acetone, in which it's soluble (USP2075179). Serullas (Pogg. Ann. 21 [1831] 165) had described the distillation of
aq. HClO3 forming HClO4: at first the watery part comes over, then viscous, colorless liquid appears and with greater heat distills over from the
retort, where chlorine and oxygen are given off at the same time.
[Edited on 7-5-2009 by Formatik]
|
|
|
| Pages:
1
2
3
4
5 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
