Sciencemadness Discussion Board - Fuming HNO3 distillation plan - suggestions?

Fuming HNO3 distillation plan - suggestions?

Rhodanide - 3-12-2017 at 11:26

Pretty soon, I plan on making some RFNA by the classic distillation method.
I Have a 500mL capacity heating mantle, a two-neck 250mL RBF, a distillation apparatus with water cooling system, an adapter with outlet leading into a 1,000 mL collection flask which I plan to use on multiple runs.
I plan on doing this outside, as I don't have a reliable way of venting gases indoors. I also have a mask, which I will wear along with all of the normal safety equipment (Though no gloves, for fire hazard mitigation). I don't have a thermometer, as it broke already so I'll be eyeballing the whole thing. I'm using very pure, refined KNO₃ and concentrated, clear & colorless H₂SO₄ (drain cleaner). It's surprisingly pure-looking, as far as drain cleaner acids go. Amounts for each haven't been measured yet, but I figure I'll cross that bridge when I come to it. What do you all suggest for a 250mL RBF? Any tips you all can give me? It's my first time doing this, and I want to make sure I don't cock it up. Recommendations? Advice? Warnings? Any and all are appreciated!
Thanks,

-R/T

metalresearcher - 3-12-2017 at 11:30

Yesterday I performed thus experiment. See this topic.
http://www.sciencemadness.org/talk/viewthread.php?tid=78668

ave369 - 3-12-2017 at 13:11

Use a finely controllable heater. Overheat means more NO2 and less HNO3.

NO2 gas may appear during the early stages of the distillation. Ignore this. If the brown gas persists, however, you might be overheating.

The distillate should be a slightly yellowish liquid with a density of 1.5 g/cm3.

Rhodanide - 3-12-2017 at 16:36

Quote: Originally posted by metalresearcher

Yesterday I performed thus experiment. See this topic.
http://www.sciencemadness.org/talk/viewthread.php?tid=78668

I saw that thread, it was 90% video editing tips and 10% other things.

Rhodanide - 3-12-2017 at 16:37

Quote: Originally posted by ave369

Use a finely controllable heater. Overheat means more NO2 and less HNO3.

NO2 gas may appear during the early stages of the distillation. Ignore this. If the brown gas persists, however, you might be overheating.

The distillate should be a slightly yellowish liquid with a density of 1.5 g/cm3.

Thanks, I also plan on turning it into WFNA by bubbling air through it.

Sulaiman - 4-12-2017 at 02:31

I have made rfna using Sodium, Potassium and Calcium Nitrates, once or twice each only, so very little experience;

IF you intend to bubble air through to get wfna then dry the air first and be aware that there is also CO₂ in atmospheric air.

/waffle on
IF you have H₂O₂ then it may be worthwhile bubbling the escaping NO₂ through some to get dilute nitric acid as a byproduct, whilst acting as a scrubber, something that I intend to try sometime.

The molar ratios required result in a slurry in the pot which gets less mobile as HNO₃ is removed,
this makes heat distribution difficult, causing hot spots which in turn produce NO₂,
so good stirring is required - or gentle patience and good heat insulation to reduce refluxing, which requires greater heat input to the pot....

I often wear my butyl rubber gloves when handling litres of conc. H₂SO₄ but equally I also like to work bare-handed as the thought of conc. H₂SO₄ being trapped between glove and hand scares me.
The combination of H₂SO₄ and HNO₃ will eat common latex or nitrile gloves.
also, I ALWAYS have a couple of 500ml squeezy bottles of saturated sodium bicarbonate solution handy just in case.

Before you start, be sure that you have a suitable container/closure for rfna/wfna storage.

So far, I have not needed to convert rfna into wfna for any of my experiments,
and I like the evil-looking rfna in a bottle on my shelf - its evilness is visible.
/waffle off

P.S. I think that a small collection flask would be better,
safety-wise and hygene-wise,
it would be annoying to ruin the product of several batch runs due to failure during one.

[Edited on 4-12-2017 by Sulaiman]

Rhodanide - 6-12-2017 at 10:37

Quote: Originally posted by Sulaiman

I have made rfna using Sodium, Potassium and Calcium Nitrates, once or twice each only, so very little experience;

IF you intend to bubble air through to get wfna then dry the air first and be aware that there is also CO₂ in atmospheric air.

/waffle on
IF you have H₂O₂ then it may be worthwhile bubbling the escaping NO₂ through some to get dilute nitric acid as a byproduct, whilst acting as a scrubber, something that I intend to try sometime.

The molar ratios required result in a slurry in the pot which gets less mobile as HNO₃ is removed,
this makes heat distribution difficult, causing hot spots which in turn produce NO₂,
so good stirring is required - or gentle patience and good heat insulation to reduce refluxing, which requires greater heat input to the pot....

I often wear my butyl rubber gloves when handling litres of conc. H₂SO₄ but equally I also like to work bare-handed as the thought of conc. H₂SO₄ being trapped between glove and hand scares me.
The combination of H₂SO₄ and HNO₃ will eat common latex or nitrile gloves.
also, I ALWAYS have a couple of 500ml squeezy bottles of saturated sodium bicarbonate solution handy just in case.

Before you start, be sure that you have a suitable container/closure for rfna/wfna storage.

So far, I have not needed to convert rfna into wfna for any of my experiments,
and I like the evil-looking rfna in a bottle on my shelf - its evilness is visible.
/waffle off

P.S. I think that a small collection flask would be better,
safety-wise and hygene-wise,
it would be annoying to ruin the product of several batch runs due to failure during one.

[Edited on 4-12-2017 by Sulaiman]

What container do you use?

Sulaiman - 6-12-2017 at 12:10

Quote: Originally posted by Tetra

Quote: Originally posted by Sulaiman

Before you start, be sure that you have a suitable container/closure for rfna/wfna storage.

What container do you use?

sorry, I'm a useless photographer.
The cap is polyethylene I think, some come with liners which I remove,
so its just glass and plastic.
Not perfect but free.
I only expected to keep this rfna for a short while so I only used a paint pen instead of one of my usual self-adhesive labels but the paint and contents seem fine after months on a shelf.

[Edited on 6-12-2017 by Sulaiman]

MrHomeScientist - 6-12-2017 at 14:41

Remember to use all-glass apparatus; distilling nitric acid will destroy rubber stoppers! Also, fill your reaction flask no more than halfway full.

One mistake I made was that the product of this reaction is potassium bisulfate, KHSO4; it doesn't go all the way to K2SO4. This precipitates out, so the reaction flask does indeed get slushy as distillation progresses.

And LOL at "suitable container" being a hot sauce bottle. If it works it works, I guess.

Rhodanide - 7-12-2017 at 07:41

Quote: Originally posted by Sulaiman

Quote: Originally posted by Tetra

Quote: Originally posted by Sulaiman

Before you start, be sure that you have a suitable container/closure for rfna/wfna storage.

What container do you use?

A Hot Sauce bottle? That's surprisingly appropriate

Rhodanide - 7-12-2017 at 07:44

Quote: Originally posted by MrHomeScientist

Remember to use all-glass apparatus; distilling nitric acid will destroy rubber stoppers! Also, fill your reaction flask no more than halfway full.

One mistake I made was that the product of this reaction is potassium bisulfate, KHSO4; it doesn't go all the way to K2SO4. This precipitates out, so the reaction flask does indeed get slushy as distillation progresses.

And LOL at "suitable container" being a hot sauce bottle. If it works it works, I guess.

I've never heard of a distillation apparatus with rubber stoppers.. seems kinda counter-intuitive with the high temperatures and all.
As for filling the flask half full only, that's because of foaming, correct?

ave369 - 7-12-2017 at 08:03

Quote: Originally posted by Tetra

I've never heard of a distillation apparatus with rubber stoppers.. seems kinda counter-intuitive with the high temperatures and all.

Old style glassware did not have ground glass connections. It used rubber stoppers. The Liebig I use is of this style, I use a lot of loops of PTFE tape as a stopper.

MrHomeScientist - 7-12-2017 at 14:16

Yep, I have a Liebig that uses rubber stoppers with holes drilled out to connect all the pieces. I tried nitric distillation with it a long time ago, but luckily the reaction failed due to too much water and I didn't damage anything!

And yes the half-full recommendation is about foaming, I believe. You don't want reactants making their way into the condenser.

aga - 7-12-2017 at 14:33

Before 24/28 etc ground glass (aka Lego Glassware) was cheaply available, people managed with Cork and Rubber.

It will not last forever, but then, neither will we, so go with what you have.

If you get some cork/rubber/carbon contamination, well, so what ?

It's not like the stuff is gonna get used for a 9 decimal place quantitative determination kinda reaction is it ?

More likely it's gonna sit in a bottle for a while before being forgotten.

Vosoryx - 7-12-2017 at 14:43

I have two 300mm allihns that are not ground glass. Completely useless to me right now, they just live in a box in my lab equipment cupboard.
The non ground glass stuff is very easy to come by - i got those two for free.

JJay - 7-12-2017 at 18:56

I'm getting ready to make some nitric acid. I'm getting everything set up tonight, but I'll probably actually mix the reagents and do the distillation tomorrow. My plan is to store it in a small, amber Boston round bottle with a Qorpak PTFE-lined cap. I've never done it before, so I'm doing a small run.

AJKOER - 8-12-2017 at 07:04

Actually, no need to make or store dangerous 'super' strength nitric acid for nitrating purposes as the nitrate radical is likely more chemically active than the acid! Just take any HNO3 and add a hydroxyl radical source, say N2O in UV light or just UV on nitric acid:

HONO2 + UV = .OH + .NO2
N2O + UV = N2 + .O
.O + H2O = .OH + OH-
NO3- + .OH = .NO3 + OH-
Or, with nitric acid: .OH + HNO3 = H2O + .NO3 (see http://adsabs.harvard.edu/abs/2001JGR...106.4995P )

For further details of subsequent reactions of .NO3 with .OH and .HO2, please see http://pubs.acs.org/doi/abs/10.1021/j100319a029?journalCode=... .

Sample run based on the UV photolysis of methanol and water in the presence of say HNO3 to create some methyl nitrate (properties: see https://en.wikipedia.org/wiki/Methyl_nitrate ):

CH3OH + UV = .CH3 + .OH
.OH + HNO3 = H2O + .NO3
.CH3 + .NO3 = CH3NO3

For other possible products, see general discussion at https://books.google.com/books?id=qmsoDwAAQBAJ&pg=PA113&...

Also, one can just use the stable radical nitrogen dioxide directly, on say, metal oxides. Per Wikipedia on NO2, to quote:

"Conversion to nitrates

NO2 is used to generate anhydrous metal nitrates from the oxides:[9]

MO + 3 NO2 → M(NO3)2 + NO "

Link: https://en.wikipedia.org/wiki/Nitrogen_dioxide

Apparently, as I recall reported once, the need to avoid rubber joints on boiling HNO3 inspired someone to use aluminum foil that became covered with anhydrous aluminum nitrate (see http://www.sciencemadness.org/talk/viewthread.php?tid=22790) .

Quote: Originally posted by Antiswat

[/rquote]
What I found interesting was that anhydrous aluminum nitrate can be prepared from AlCl3 in N2O4 at 0 °C.

[Edited on 23-12-2012 by AndersHoveland][/rquote]

A bit off topic, but when ive made Pb(NO3)2 by HNO3 + Pb i have covered my flask with 10 layers of aluminium foil, and apparently the NO2 formed can and WILL react with the aluminium foil to make aluminium nitrate, infact this reaction is probably taking place right now, just thought its weird that aluminium wont react with HNO3 but NO2 reacts with aluminium

[Edited on 8-12-2017 by AJKOER]

[Edited on 8-12-2017 by AJKOER]

nitro-genes - 9-12-2017 at 15:07

IMO, using KNO3, a 30% excess of sulfuric increases yield, decreases NOx and makes cleaning the heating flask afterwards more easy due to increased fluidity. Another thing to remember is that the dissolution of KNO3 in the sulfuric is very exothermic, be sure that most KNO3 has dissolved in the sulfuric BEFORE you start heating, the excess sulfuric also helps here. This is more annoying than a problem: when the sulfuric is poured direclty on the powdered KNO3 without stirring, it forms large lumps that break up with difficulty, even during heating. So better add the KNO3 to the sulfuric with stirring. HNO3 decomposes slowly at higher temperatures, so insulating the heating flask and neck up until the condensor will prevent excessive refluxing, shorten the distillation, increase yield and produces less NOx. IMO, keeping the height between the fluid level and condensor inlet to a minimum is most efficient. Also, >90% HNO3 is reasonably volatile even at room temperature, is decomposed by UV light and has a limited shelf life in storage, so best kept on ice, especially when working with it in open beakers etc to minimize exposure to nitric/NOx. If your goals is the highest strength HNO3, KNO3 in combination with a vacume is best. Using ammonium nitrate will generally produce less NOx and result in HNO3 with less nitrogen oxides dissolved, typically of slightly less strength though (>95 vs 90-95%).

[Edited on 9-12-2017 by nitro-genes]

NEMO-Chemistry - 9-12-2017 at 21:16

Quote: Originally posted by Vosoryx

I have two 300mm allihns that are not ground glass. Completely useless to me right now, they just live in a box in my lab equipment cupboard.
The non ground glass stuff is very easy to come by - i got those two for free.

I got alot of non ground glass stuff, I got some cork bits although cork seems hard to get. I also have some ground glass (different sizes) and various adapters to fit it together.

When you consider the beginnings of science, we got it easy. Look at all the really great fundamental discoveries, non where done with ground glass.

I wrap cork or rubber stoppers in PTFE tape, if you think about it.. The single most important bit of equipment in science, is the mind. Glass is just sand without a brain to see beyond it.

Look at many threads, people stress over 0.0000 stuff and yet buy or make reagents within 3-5%???

Anyone seen the documentary on LE GRANDE?? Thats a shed load of of fuss over nothing!! Made me laugh when the guy was dead serious and said, " Even with modern tech, LE Grande is loosing) X molecules per whatever it was.

To correct this absolute catastrophe they have a guy making a new one, a perfect round sphere. Yet he is doing it by hand with a bit of rag!

nitro-genes - 10-12-2017 at 15:36

When no glassware available, a pretty decent air cooled condenser can even be made from an old fluorescent tube, actually distilled my first nitric this way.

[Edited on 10-12-2017 by nitro-genes]