greenyppols - 16-1-2006 at 10:03
Im posting this hoping to get advice while Im still doing this, pls bear with me, I am following Prep 7, Method 1 in Kings Chemistry survival guide
for Nitric Acid.
200ml H2SO4 cooled to 0ºC in ice bath, added 100g KNO3 over 1 hr with stirring then added 260ml H2O over 1 hr also maintaining 0ºC.
Currently xtracting 10 times with 100ml DCM. 1000ml DCM total. (I dont have the amount needed, 1050ml, figured 50ml difference wont matter)
I have yet to add 27ml water later in the procedure, Im in the extraction section yet.
I see a by-product is potassium sulfate...is this what is beginning to 'sludge up' and is it ok to filter it out? Its getting kinda thick and I havent
extracted with 400ml yet and have 600ml to go.
Any idea how much nitric I may expect? I read I could expect the same amount in nitric as KNO3 I used, but I cant find where I read this.
This is alotta solvent for Nitric, I think, but it seemed easier for me to go as I didnt need to heat it, only extract it and then distill off the
DCM, which is a much lower temp that other methods I've read involving heating...reduced pressure, etc.
I searched the forum but didnt see anything pertaining to this and thought I'd ask if someone was familiar with this procedure.
Thanks
[Edited on 17-1-2006 by greenyppols]
Nitric acid
MadHatter - 16-1-2006 at 10:21
The search engine may not reveal any hints for the method you're using but it will come up
with plenty on nitric acid production. As for yields, that will depend up the concentration of
your H2SO4. Yields of HNO3 from KNO3 ? Maximum theoretical yield by weight is 62%.
This is based on atomic weights: KNO3 = 101, HNO3 = 63. You don't need DCM in the
distillation process. Standard distllation can give you 68-70%. With vacuum distillation
it's even higher.
greenyppols - 16-1-2006 at 16:20
Thanks Madhatter, I used DCM as that's what that particular procedure instructed...
I had checked the other routes to Nitric but thought I'd give this one a try, for reason mentioned...my vacuum distillation plans had a monkey wrench
tossed in it when I realized I have to concoct a cold and acid trap.
I know what Im going to be doing all freakin' day tomorrow, I have 1000ml of extracted DCM to distill and recover. I'll post what amount of Nitric I
end up with...It doesnt look like its gonna be much though...the excitement is killin' me. or lack of..
[Edited on 17-1-2006 by greenyppols]
1st H2O3 results and a pic
greenyppols - 17-1-2006 at 13:43
Distilling off the DCM took around 8hrs and the result was approximately 50ml. I have need of graduated cylinders yet obviously.
Im sure I'll go another H2O3 route next time...removing 1000ml DCM was too much work for this...to me, anyway. Didnt know what to expect though, but
now I know. This experiment was simple enough, if time consuming.
I wouldnt recommend this route. But..what do I know but this one yet? lol.
I attached a pic of the nitric if you like pics!
Fleaker - 17-1-2006 at 16:58
IIRC the DCM method is used at low temperatures (as in the LN2 range) when you want absolutely anhydrous nitric acid. It seems like a waste of time to
use DCM if you're just after the ~70% stuff, I'd just heat a nitrate salt with concentrated sulfuric acid in a distillation set up with a teflon stir
bar (remember to keep it hot, or that sludgy sulfate with thicken and congeal). Some sources recommend the use of a vacuum @ 0C to pull the nitric
acid over, but Rosco has informed me that it is unnecessary.
Magpie - 17-1-2006 at 17:59
Search and read "making own nitric acid." It recounts my recent experience in making 68% nitric acid, as well as the experience and recommendations
of others. With the right equipment and ventilation it is straightforward enough. No DCM or vacuum involved. 
greenyppols - 17-1-2006 at 18:04
Fleaker, I will NOT be doing this particular route again...I just figured what the heck, I didnt see a low temp route here or mention and decided to
try. I wont be again if 50ml is all to expect.
"Anhydrous" anything is beyond my skills at this point. lol. Except for absolute ethanol via 3a molecular sieves..but thats kinda cheating. hehehe
I had considered the higher nitric concentrations in the other methods in the book, but seeing as how I didnt know what to expect, I played safe.
Considering that I added 27ml of H20 to the extracted DCM before distilling it off, I'd have ended up with even LESS if I had not. Live n Learn.
I'll try another route to Nitric if I try it again, but Im just tinkerin' around and honing my skills, and learning (pats self on back) from the great
books you provide via FTP.
[Edited on 18-1-2006 by greenyppols]