BPinthemorning Posted September 26, 2007 Posted September 26, 2007 Can potassium nitrate replace nitric acid in a gun cotton mixture, and can sulfuric acid from drain cleaners be used? Also, what are alternative sorces of nitric acid? I read it could be bought at a pharmacy. If so, what is it sold as?
frogy Posted September 26, 2007 Posted September 26, 2007 You don't get info like that unless your in HE.... There is no discussion of synthesis of NC or any HE unless it is in the HE section... Don't continue... If you really need to know, search google, don't ask here or you'll get in trouble
BPinthemorning Posted September 26, 2007 Posted September 26, 2007 Crap! guncotton is a HE??? Dang! Sory!! I didn't know. I will stop aking about it.
tentacles Posted September 28, 2007 Posted September 28, 2007 Have a question about HNO3 synth - when using KNO3 or NaNO3, the equation should be: xNO3 + H2SO4 -> xHSO4 + HNO3 correct?and with CaNO3:Ca(NO3)2 + H2SO4 -> 2HNO3 + CaSO4 Would these equations be correct?
Mumbles Posted September 28, 2007 Posted September 28, 2007 They are reasonable correct yes. There will probably be some equilibrium between the bisulfate and sulfate in the Na or K equation depending on how much sulfuric acid is in there. It should be noted that in order to get a reasonable separation of the calcium sulfate and nitric acid, the nitric acid has to get fairly diluted from washings and what not unless you have access to a pretty good strength vacuum pump and acid proof filter.
tentacles Posted October 11, 2007 Posted October 11, 2007 mumbles, what kind of yield should I expect from: 200ml H2SO4 + 615g Ca(NO3)2 (est 310ml yield) 200ml H2SO4 + 319g NaNO3 (est 155ml yield) Also, what can I do to improve yield - I got about 300ml using 450ml H2SO4 + 615g Ca(NO3)2 + 319g NaNO3. I had even added a weak previous batch of HNO3 to the RBF. It seems like I should have gotten more around 500ml. The weak HNO3 that was added was about 1.29SG 150ml. The current batch is about 1.44-1.48SG, my big bottle's graduations aren't so great even after a bit of calibration. Most of the HNO3 vapor was coming over between 55-65C, with the RBF in 65C water for most of the duration. Towards the end I drove the water as high as 80C, and stopped when it didn't want to boil much anymore. There was still some liquid in the RBF, but it wasn't fuming much and I expected at least some from the extra H2SO4 and the water from the weak HNO3. I used tap water to drive the vacuum aspirator (20-25" Hg) and the effluent was used to cool the condenser. Probably like 50F, once we're in winter it'll drop to like 38F. Are my ratios off, am I doing something wrong?
Mumbles Posted October 11, 2007 Posted October 11, 2007 Lets see. I just converted everything roughtly to moles to make this easier to look at. 3.6 H2SO4 + 3.75 Ca(NO3)2 ---> ~7.2mol HNO3 + 3.6CaSO4 3.6 H2SO4 + 3.75 NaNO3 ---> 3.6 HNO3 + 3.6 NaHSO4 So, that should have theoretically yielded around 11 moles of HNO3, in a pure form. Thats 447 of 100% acid. The 1.29 stuff should be around 50ish %, and the high conc stuff is between 80 and 95%. There is kind of a flat area in there. I would expect that even low concentration nitric would have distilled over at those temperatures. The liquid may have been H2SO4. The calcium sulfate may have drapped some of the desired product as a cathrate. It may be kind of a confusing term in the amateur chem community, but it's a molecule of one thing trapped inside another. Generally the term is associated with azocathrates. In this case, some of the nitric could be trapped in the crystal structure of the CaSO4. You'd have to heat it more vigorously to get it to be released. Pressure would have no impact on it. Thats about all I can think of, unless your condensor wasn't efficient enough(though it should have been), and the acid vapor was getting sucked out.
tentacles Posted October 11, 2007 Posted October 11, 2007 Thanks, mumbles, that may have been what happened - as I had a nice hard crusty chunk in my RBF when it was cleanup time. I'll try another batch with a bit more excess H2SO4. Is there a methodology I should be following as far as combining the acid and nitrate? ie nitrate in RBF, pour in acid, vice versa, etc? I've been pouring the acid on the nitrate, and then "stirring" with a piece of 304 stainless wire. It hasn't affected the wire yet than I could see. I'd really like to find a way to make the Ca(NO3)2 work, because the efficiency is much higher for the reaction, than the other nitrates. And it's H2SO4 that's the main cost consideration, the nitrates all cost about the same. The spiral condensor worked wonders for me, too - most of the vapor condensed in the first 3 inches. It will be interesting to see if the efficiency goes up this winter.
asilentbob Posted October 11, 2007 Posted October 11, 2007 There is a theory that H2SO4 binds HNO3 as it does water to some extent.. or atleast i htink i heard that somewhere. There is always DCM extraction...
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