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plante1999
International Hazard
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Quote: Originally posted by Nicodem  | | If applying a gassing setup is too troublesome for you, you could consider doing the reduction of nitric acid in situ. Dilute nitric acid
can not effectively O-nitrate alcohols while the nitrous acid can O-nitrosate them. Therefore a mixture of diluted (say 1 or 2M) nitric acid and
isopropanol might give isopropyl nitrite if a reducing reagent such as copper is used (the blue of the copper will additionally make for the kewlish
color effect, if kewlishness is your thing). Use about 4 equivalents of HNO3 over isopropanol and apply good stirring. It might not work, but at least
it is effortless. |
Wow this was a really really great idea!
I mix 40g of water 16g of ammonium nitrate 30g of 95% H2SO4 to make my HNO3 sol. , I poured it in a flask in a bucket of cold water.
Then I added 2g of copper and all 12g of isopropyl alcohol 1ml each 45 second to the nitric acid. then the last 12g of copper where added(slightly
more than needed).
The reaction is running really slowly giving no nitrogen oxides and after 15minutes there was a yellow green layer forming on top! The reaction is
still running overnight and I expect really great yield. thanks Nicoderm! tommorow I will test my product. How can I clean the isopropyl nitrite?
2NH4NO3 + 2Cu + 3H2SO4 + 2IPr(OH) -) (NH4)2SO4 + 2CuSO4 + 4H2O + 2IPr(NO2)
thanks all!
I never asked for this.
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plante1999
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Isopropyl nitrite purity
I made some isopropyl nitrite but I am not sure if it is isopropyl nitrite.
How can I test it? Also I want to wash it and I dont know how to do it.
My isopropyl nitrite is a yellow-green liquid making a layer on saline solution.
The isopropyl nitrite is for azide production.
thanks!!!
[Edited on 17-5-2012 by plante1999]
I never asked for this.
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Mailinmypocket
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Are you looking to determine purity in the sense of contaminants present in the final product or are you looking for a way to find out if the product
is isopropyl nitrite?
By your description it sounds identical to the isopropyl nitrite I made. You could trythis test for nitrites, it applies to aqueous nitrites and I'm not sure if it would work for alkyl nitrites given the insolubility in water... Im
fairly sure you have isopropyl nitrite though.
Care to share the procedure you followed? I used the one from len's book "Small-Scale Synthesis of Laboratory Reagents with Reaction Modelling" and it
worked very well.
Washing can be done by shaking with distilled water and separating the phases, repeat 2-3 times. I dried mine over anhydrous sodium sulfate also.
[Edited on 17-5-2012 by Mailinmypocket]
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Nicodem
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Threads Merged
17-5-2012 at 09:22 |
Nicodem
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That is a nice and illustrative example of an oxymoron. You can use the derivatives of the word "presume" for declaring identity without having any evidence. It sounds better and you don't end
up contradicting yourself.
| Quote: | | How can I test it? Also I want to wash it and I dont know how to do it. |
First the most elementary data: What is its boiling point?
Separatory funnels are the equipment used for performing washings or any other operation involving liquid-liquid phase separation. Alternatively,
for small volumes, you can use a pipette to separate phases.
| Quote: | | How can I clean the isopropyl nitrite? |
Volatile liquids are generally isolated and purified by distillation, usually using a fractionating column if the contaminants are also volatile.
Edit: You should use at least 3 to 5 times more water in your experiment. The reaction mixture is too concentrated - formation of nitrates can be a
competitive reaction at such conditions. Formation of a liquid layer is also no conclusive indication of the desired esterification, because
isopropanol forms a biphasic mixture with aqueous solutions of many salts (it "salts out").
Also, don't cross-post anymore. Opening another thread on the topic and furthermore without giving the reference to this previous discussion, like you
did, can only cause confusion. Read the forum guidelines for posting.
[Edited on 17/5/2012 by Nicodem]
…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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Scr0t
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I made this by passing SO2 from a Sulfur burner/candle into HNO3 (100ml) according to Brauer.
I used the suction of a water aspirator to draw SO2/air through the apparatus. However the aspirator flow rate wasn't really sufficient (it took 12hrs
to burn ~100g S, theoretical predicted ~5hrs) by which the point the HNO3/NOHSO4 mix had become yellow, viscous and opaque with small gas bubbles in
suspension, no solids had separated.
Addition of this liquid to an equal volume of AcOH caused immediate deposition of white solids that were filtered and dried in a desiccator. Yielding
only 42% NOHSO4 based on HNO3, I may have been too liberal with the AcOH.
The material rapidly reacts with water to generate a blue-green liquid and copious amounts of NOx.
An earlier attempt on the same scale above which used a wet slush of Sodium Metabisulphite and dropwise addition of aqueous H2SO4 (50% /v) to generate
the SO2 proceeded smoothly at first but after about half the acid had been added SO2 generation became erratic causing the mass to heave releasing
strong bursts of SO2.
By the the time I considered disconnecting the generator the HNO3 suddenly began boiling, blowing out the Dreschel head and spraying hot HNO3/NOHSO4
for several feet in-spite of the ice-salt bath cooling.
So if Metabisulphite is used then use much more water and a very gradual temperature ramp to drive out dissolved SO2.
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AndersHoveland
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| Quote: Originally posted by hissingnoise | When NH<sub>4</sub>NO<sub>3</sub> is dissolved in a large excess of H<sub>2</sub>SO<sub>4</sub>
nitramide NH<sub>2</sub>NO<sub>2</sub> is formed.
No handy reference woelen, but it's dehydration by excess sulphuric acid; NH<sub>4</sub>NO<sub>3</sub> minus
H<sub>2</sub>O ---> NH<sub>2</sub>NO<sub>2</sub>.
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As for trying to dehydrate ammonium nitrate with sulfuric acid,
| Quote: |
When ammonium nitrate is heated with a large excess of concentrated sulfuric acid, about 85% of its nitrogen is given off as nitrous oxide, the rest
in its elemental state. The dehydration does not become rapid until 150 °C.
"The Dehydration of Ammonium Nitrate", Tenney L. Davis, Armand J. J. Abrams, J. Am. Chem. Soc., 1925, 47 (4), pp 1043–1045
"Ammonium nitrate heated with two equivalents of sulfuric acid behaves in the normal matter and yields nitric acid" [rather than dehydration of the
ammonium nitrate]
Pelouze, Ann. chim. phys., [3] II, 47 (1841)
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In another topic in this forum, "Why can concentrated sulfuric acid not be used to make RDX ?", one of our members posted a Chinese reference
which stated that RDX reacts with sulfuric acid to form formaldehyde, nitrosylsulfuric acid, nitrogen, and water. Presumably the acid causes
hydrolysis of the RDX first, and then the NH2NO2 immediately reacts.
| Quote: |
(CH2NNO2)3 + 2 H2SO4 --> 3 HCHO + 2 O2S(OH)ONO + 2 N2 + NO2
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So the dehydration of NH4NO3 with H2SO4 might indeed be a route to prepare nitrosylsulfuric acid, if dehydration to
nitramide can initially happen as an intermediate.
On the other hand, I would think nitrosylsulfuric acid would immediately react with any nitrate to liberate nitrogen dioxide.
NO3- + NO+ --> 2 NO2
Is this NO2 going to just escape from the reaction? Or will it be transformed into something else?
(NO2 is known to be able to slowly oxidize NH4+, particularly in boiling solution, but this potential reaction pathway is probably not going to be of
any importance here since the NO2 is likely to go somewhere else first)
Although these references I have presented may not seem to support hissingnoise's assertion, I am still inclined to think that nitrosylsulfuric acid
could be formed. It might be best to gradually add the NH4NO3 to a large excess of conc. sulfuric acid.
I am not entirely sure, but I suspect the NO2 would be withheld in highly concentrated sulfuric acid, in the form of nitronium hydrogen sulfate,
together with nitrosylsulfuric acid. (nitronium hydrogen sulfate exists, at least as an intermediate, in common mixed acid nitration reactions)
| Quote: Originally posted by Nicodem | | If applying a gassing setup is too troublesome for you, you could consider doing the reduction of nitric acid in situ. Dilute nitric acid can
not effectively O-nitrate alcohols while the nitrous acid can O-nitrosate them. Therefore a mixture of diluted (say 1 or 2M) nitric acid and
isopropanol might give isopropyl nitrite if a reducing reagent such as copper is used (the blue of the copper will additionally make for the kewlish
color effect, if kewlishness is your thing). Use about 4 equivalents of HNO3 over isopropanol and apply good stirring. It might not work, but at least
it is effortless. |
Except that isopropanol is fairly vulnerable to oxidation. If left to stand for any length of time with moderately concentrated nitric acid, it is
likely to be initially oxidized to acetone, and then rapidly to further oxidation products (since acetone tautomerizes to its enol, especially under
acidic conditions). Nicodem, your proposed reaction route might work better with ethanol or methanol... or n-propyl alcohol...
Nitrous acid might have a much faster reaction rate, but even moderately concentrated nitric acid is a more powerful oxidizer (because of
nitronium NO2+ ions in equilibrium).
[Edited on 20-2-2013 by AndersHoveland]
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
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