That's not very different from the way we made "Tri-Nitro-Toilet_tissue"
(actually, nitrocellulose, or guncotton) when I was an undergrad.  We
soaked rolls of toilet tissue in concentrated solutions of nitric and
sulfuric acid, then rinsed the rolls in water.  It still looked like
toilet paper, but was actually now "flash paper" that would burn very
rapidly with a great yellow flash and practically no smoke.  Don't try
this unless you know how to handle concentrated acids.

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Gun Cotton
Date: 17 Feb 1996 07:19:49 GMT

In article <Pine.Sola.3.91.960216214026.24052B-100000@ux5.cso.uiuc.edu>,
brown michael david <mdbrown2@ux5.cso.uiuc.edu> says:

>On Fri, 16 Feb 1996, Kubla Khan wrote:
>
>> The proportion of H2SO4 is by no means sacred.  I believe the 
>> H2SO4 is part of an intermediate process. The H2SO4 replaces the 
>> hydroxyl groups initially, and (in a few steps) is replaced 
>> eventually by the nitro group, regenerating the H2SO4 ( a catalyst,
>> I guess).  This is why the pure HNO3 reaction is so miserably slow.  
>> The reaction time for a significant number of hydroxyl groups to 
>> be replaced by nitro groups is very slow, while the reaction time 
>> for SO4-- to replace hydroxyl groups is much faster. Also, H2SO4 
>> helps keep the pH nice and low.
>
>Actually, it was a rhetorical question. I didn't expect an answer. As for 
>your guess, I'll give a hint and then you can report back.
>
>Hint: nitronium ion formation
>
>What the hell, Hint #2: In mixed acid, nitric acid acts as a base
>
>Let us know what you come up with.


Either you know or you don't know; we don't need no stinkin' hints :)

2HNO3 <-> NO2(+) + NO3(-) + H2O

The nitric acid is not a base - it is the "medium," analogous
to water in the more conventional acid-base reactions you 
learned in elementary chemistry. Both H2O and NO3(-) shift the
equilibrium to the left, thus depressing the activity of the
nitronium ion which is the effective nitrating species. It is 
the nitrate ion which is analogous to a base in this system.

The nitronium forming equilibrium mechanism shown above also 
explains why nitration efficiency is depressed in the presence 
of metal nitrates.

Sulfuric acid is both a very a powerful dehydrating agent and
a very strong acid in this system. It therefore promotes 
nitronium formation by decreasing both the H2O and the NO3(-)
on the right-hand side of the equation and slightly increasing
the HNO3 on the left - a TRIPLE whammy..

H2SO4 + H20 -> H2SO4:H2O (water decreased)

H2SO4 + NO3(-) <-> HNO3 + HSO4(-) (HNO3 slightly up, NO3(-) down) 

Jerry (Ico)

P.S. Kubla, if you are following this thread. please throw in some
carriage returns in your next post. I took the liberty of
shortening your lines for this post. Thanks. 

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Gun Cotton
Date: 17 Feb 1996 21:25:29 GMT

In article <Pine.Sola.3.91.960217094206.1312A-100000@ux4.cso.uiuc.edu>,
brown michael david <mdbrown2@ux4.cso.uiuc.edu> says:

>On 17 Feb 1996, Gerald L. Hurst wrote:
>
>> Either you know or you don't know; we don't need no stinkin' hints :)
>
>Okay, no more hints :)
>
>> 2HNO3 <-> NO2(+) + NO3(-) + H2O
>> 
>> The nitric acid is not a base - it is the "medium," analogous
>> to water in the more conventional acid-base reactions you 
>> learned in elementary chemistry. Both H20 and NO3(-) shift the
>> equilibrium to the left, thus depressing the activity of the
>> nitronium ion which is the effective nitrating species. It is 
>> the nitrate ion which is analogous to a base in this system.
>
>I'll agree with the above when you're talking about nitric acid alone, 
>that small amounts of nitration occur and that the speed of reaction is 
>determined by how fast nitronium ion is formed.
>
>But, when using mixed acid (HNO3 & H2SO4) the weaker nitric acid does 
>indeed act as a base.
>
>HNO3 + 2 H2SO4 <==> NO2(+) = H3O(+) + 2 HSO4(-)
>
>This has been confirmed by Raman spectroscopy ("Advanced Organic 
>Chemistry", by March & "Organic Chemistry", by Morrison and Boyd).

What "This" is confirmed? That such a reaction occurs when nitric
acid is added to sulfuric acid? Certainly something of this
sort occurs as is shown by freezing point depression. However,
the nature of the four "particles" formed in the solution is
highly debatable. The question is whether your "this" is a 
validation for saying that nitric acid is acting as a "base"
in the reaction sequence. Obviously, the HNO3 is "basic" to the
extent that it accepts protons from the H2SO4 at the first
(unwritten) stage of the formal reaction sequence. However, if
this constitutes its being a base then we would by that same 
reasoning call water a base in a bottle soda pop:

H2O + H2CO3 <-> H3O(+) + HCO3- 

Even if the statement is "true" as a formality, it is in 
conflict with our conventional chemical paradigm which
treats the solvent as a "medium" to prevent reaching the 
conclusion that water is a base in the presence of 
carbonic acid, a "base" which produces hydronium ion. We do
this by convention even though a specialist school might
hold that the bicarbonate ion is to the H2CO3 acid-base
system what OH(-) is to the aqueous system. 

Note that in the textbook equation, the justification for 
labeling HNO3 as a base is the appearance of HSO4(-) in the 
products, i.e., the definitive base moiety in the H2SO4 solvent
system. From this viewpoint we are then forced to recognize 
HNO3 as a "base" which produces hydronium ion. Can we do this?
Sure we can, but if we do, we must also add a lot of 
system-defining verbiage because we are stepping outside
the current default paradigm for acid-base discussions. 

The equation you abstracted from the textbooks is one of
a number of model viewpoints from which we can choose
to look at the complex equilibria and associations of the
species in the mixture. I suggest that you review the more 
useful equations that I provided. They answer more questions 
about the behaviour of nitrating systems than the textbook 
equations do.

Perhaps the best example I can give you is that my suggested
equations correctly answer the classic teenybomber question,
"Can I use saltpeter or sodium nitrate with sulfuric acid
to make ......? " If you are already smart enough to understand
the equations, the answers lie therein :)

For those who joined the discussions late, the equations 
referred to were discussed in some detail in my previous post.
I'll cite a fine reference if I can ever dig it out of the 
paper jungle.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Gun Cotton
Date: 21 Feb 1996 03:58:30 GMT

In article <BILLW.96Feb20183550@puli.cisco.com>, billw@puli.cisco.com
(William ) says:

>    Sulfuric acid is both a very a powerful dehydrating agent and
>    a very strong acid in this system. It therefore promotes 
>    nitronium formation by decreasing both the H2O and the NO3(-)
>    on the right-hand side of the equation and slightly increasing
>    the HNO3 on the left - a TRIPLE whammy..
>
>But the nitrocellulose processes I've read about (Davis) don't use highly
>concentrated acids, so presumably the dehydration capability isn't as much
>of an issue.  Or are the concentrations stil essentially "water free", and
>just lacking in excess sulfer/nitrogen oxides?

My post was directed to nitrations in general. Some materials 
nitrate more readily than others. If you want to discuss a 
particular technique for making nitrocellulose you need to
be a little more specific about the nature of the procedure
and the yield and degree of nitration of the product. Nitrations
often begin easily with the introduction of the first -NO2 
group and then get progressively more difficult.

A term like "highly concentrated" doesn't mean a great deal to
me. If you are referring to a procedure for highly nitrating
cellulose then you probably need H2SO4 to keep your nitric
acid effectively "concentrated" by removing water formed as
a byproduct in the nitration.

Jerry 

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: rec.pyrotechnics
Subject: Re: Gun Cotton
Date: 20 Feb 1996 21:41:01 GMT

In article <4gcsge$kfo@due.unit.no>, atlesi@stud.unit.no (Atle Silgjerd) says:

>By the way the discussion on why the water was present in the 
>nitrating mixture: The water comes from the HNO3 acid, which
>can't contain 100% HNO3. (I think the most concentrated form
>is about 65-70%) 

Sure it can. Nitric acid  also exists as the 100 percent
material, but more often one finds the so-called fuming
nitric acid which is a solution of NO2 in the strong aqueous
acid. 100% HNO3 does tend to decompose rather easily.

Jerry (Ico)

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Ask Me Anything...
Date: 13 Jun 1996 04:34:08 GMT

In article <4pldqd$k9n@crl3.crl.com>, gherbert@crl.com (George Herbert) says:

>Gerald L. Hurst <glhurst@onr.com> wrote:
>>What is the value of the equilibrium constant for the reaction below?
>>2HNO3 <--> H2O + NO2+ + NO3-  
>
>Must be pretty low, White Fuming Nitric Acid doesn't generate NO2/N2O4
>by itself (but woe be you if you put it in a metal container...).

Read the equation again.  There is no NO2 or N2O4 involved -- the 
nitrogen-containing species on the right are ions.  The values of 
the constant in question under various conditions would be a useful 
bit of data for estimating the effects of the various species 
concentrations on the velocity of nitration reactions.  It would also 
be useful to know the value of the analogous reaction in a sulfuric 
acid medium where the concentration of water is essentially nill but 
the common ion effect of the nitrate remains in play.

Jerry (Ico)  

From: glhurst@onr.com (Gerald L. Hurst)
Newsgroups: alt.engr.explosives
Subject: Re: Nitrocelulosa
Date: 29 Aug 1996 22:25:35 GMT

In article <504cuq$rg9@news.burgoyne.com>, dlj@burgoyne.com (David
Jensen) says:

>Know also that when Superdave refers to concentrated nitric acid, he
>means fuming nitric acid, above 90%.  That is not the same as the
>azetropic acid (ca. 63%) more commonly available.
>
>Some explosive substances, such as Picric Acid, don't require fuming
>nitric acid in their synthesis.

I'll bet that Superdave, being a super chemist, meant what he said: 
concentrated nitric acid, i.e., HNO3 in less than half its weight 
of water.  The role of the sulfuric acid is effectively to  reduce
the water concentration and thereby allow a shift to the right in
the equilibrium

	2HNO3 <--> NO2(+) + NO3(-) + H2O

The end effect is as though a more concentrated acid had been used.

The azeotrope contains 78% HNO3 rather than 73%.  Comercial nitric
acid is about 71-73% HNO3.  Pure HNO3 is less common because of its
instability - it is decomposed by light. The pure acid is a fine 
nitrating agent but soon loses its potency because of the formation
of water during nitration reactions.  It follows that for most such
reactions it is more convenient to use the more stable watered acid
and a lot of sulfuric acid.  The spent nitric acid can then be 
recovered by distillation from the sulfuric acid and recylcled 
indefinitely.

Fuming nitric acid is actually a solution of NO2 in concentrated 
nitric acid.  It too is a potent nitrating agent and a rather nasty
material, even compared with the more common laboratory acid.

Jerry (Ico)

	

From: Will Flor <willf@rrgroup.com>
Newsgroups: alt.engr.explosives
Subject: Re: Nitrocelulosa
Date: Thu, 05 Sep 1996 10:15:18 -0500

David Jensen wrote:

> Gerald L. Hurst wrote:
>
> > Fuming nitric acid is actually a solution of NO2 in concentrated
> > nitric acid.  It too is a potent nitrating agent and a rather nasty
> > material, even compared with the more common laboratory acid.


That's red fuming nitric acid - the stuff we used at Trojan was
amost 100% nitric acid and was called (and labeled) "white fuming
nitric acid" and definitely didn't contain any NO2 - it was clear.


> People in these silly newsgroups don't want to know fact, they want to
> argue.  You can make cellulose nitrate plastic with azeotropic nitric
> acid.  But to get guncotton - the stuff that explodes - the
> stuff approaching the theoretical limit of 14.14% nitrogen - you will
> need more concentrated nitric acid than that.  You can add all the
> sulfuric acid you want, as a dehydrating agent, and you will still not
> end up with guncotton.


Guncotton isn't really all that close to the 14.14% limit - the
stuff that is is called "cotton of ultimate nitration" and is
definitely "higher test" than anything I've seen called "guncotton."

> While I am deeply grateful for your educated treatise on nitric acid,
> Jerry, I suspect you've never successfully made guncotton.  And now you
> know why.

The only times I've ever nitrated cotton, it was with the 
aforementioned white FNA - not azeotropic HNO3, nor red FNA, which I've 
never worked with.  The finished product was definitely cotton of
ultimate nitration - you could put a big ball on your hand and 
ignite it, and the ball would disintegrate instantly, and you would
feel barely any heat on your hand.  That stuff is very sensitive
to friction, heat, etc. so be very careful.


-Will Flor                willf@rrgroup.com
Former explosives chemist, Trojan IMC
Spanish Fork, UT and Wolf Lake, IL plants

From: arno@utu.fi (Arno Hahma)
Newsgroups: rec.pyrotechnics
Subject: Re: nitro, who has tried it realy =O-/   ?
Date: 15 Aug 1996 19:15:32 +0300

In article <jbatistaDw3zqK.9so@netcom.com>,
Jose Batista <jbatista@netcom.com> wrote:

>I agree with doc ditto. You do not want to screw with nitro glycerin, you 
>WILL die.

Well, then I am multiply dead ;-). Nitroglycerol is
sensitive, but it is far from the movie nonsense. If you
drop a droplet on floor, it just splashes around like any
oily liquid. If you ignite a small amount, it burns like
alcohol, with a colorless flame. 

It explodes, if you hit it under confinement, such as throw a glass
bottle entirely full (no trapped air) of it against a concrete wall.
Still, odds are, that it only splashes around, I wouldn't bet, though.
NGl also explodes, if you fill a .22 casing with it, close the casing
with a tong and hit it hard with a hammer on an anvil. That makes an
awful lot of noise inside a room and a lot of small shraphel, BTW.

Another nice way to detonate it: fill a piece of melting point
capillary tube with it, close one end by heating with a propane torch
and then close the other end, too, avoiding the NGl from touching the
flame. Then expose the column of NGl to the flame and you've got an
instant, very bright flash with a loud report.  Of course,
you will want to hold the tube with a tong during the whole
operation.  Only a few ten mg are needed for this demonstration. Note,
that both ends of the capillary tube have to be melted close, otherwise
the NGl will just boil and spit itself out of the open end(s) of the
tube.

NGl keeps just fine in a fridge (I've had a bottle of it there for more
than 2 years, it is still there and the fridge is still there), just
stabilize it with acardites or centralites or calcium carbonate. It
freezes under +13 oC, unless some ethyleneglycol dinitrate has been
added or if the NGl is very pure. Pure NGl supercools easily
down to 0 oC, impure freezes.

I still don't recommend making NGl, since the chemicals involved are
not nice to handle. It also creates unstable waste acid, that may
decide to cook off any day, unless you denitrate it. Don't dilute the
acid, unless you are able to dump it into a large excess of cold water
with an efficient stirring.  Diluting the acid may trigger a cookoff
reaction.

I've had such a cookoff once, it is not nice, you get a shower of acid
all around.  Fortunately, I noticed what is happening and moved the
bottle outside well in time. The positive part of it was, that I
didn't have to empty the bottle nor get rid of the acid.  It did
that all by itself ;-). All I needed was a hose to rinse the
bottle and the surroundings.

ArNO
    2

Newsgroups: rec.pyrotechnics
From: tip@ai.chem.ohiou.edu (Tom Perigrin)
Subject: Re: TOM PERIGRIN
Date: Sat, 4 Jan 1997 19:59:35 GMT

In article <32CE5FAD.2B6F@uiuc.edu>, Mike Brown <mdbrown2@uiuc.edu> wrote:

> KN03 wrote:

[snip]

> > NO2 is the reddish brown gas that is given off when most metals are
> > dissolved in HNO3, right?
> > It has a very unpleasant smell, not quite as sharp as SO2, but it will
> > make you choke, to say the least.  I've been there and done that. I don't
> > see how you could inhale enough of it to damage your lungs, without being
> > aware of it.  At least I'm still walking around.
> 
> 
> I said *can be*. I've done nitrations that realeased NO2,
> and if I inhaled it I didn't feel it. Your *been there
> and done that* attitude suggests that you think it's no
> big deal. Do you know what a fool's death is?


The Merck Index lists NO2 as one of the most insidious of gases, since you
can easily inhale a lethal dose from a concentration that is far below
detectability by the nose.


[snip]

 
> Likewise, small amounts of NO2 that won't kill you will
> still scar your lungs. This is an additive effect that
> leads to severe reduction in lung capacity. There are
> some here that know people that suffer from just that
> effect.


When I was a kid, I used HNO3 and other chemicals with wild abandon.  Hell,
when I was kid we were still called "alchemists" (well, maybe not _that_
old).  I breathed NO2, and coughed up chunks...  Thought it was "cool",
since I was living life on the edge... asshole kid.

When I was a student, we used benzene like water... I spilled oil onmyself
once, and washed it off with benzene...  breathed a lot of vapors.

Nowadays, I have a lot of lung ailments.  I get pneumonia almost every
winter.  A few years ago a pneumonia put me into the ICU Pulmonary Unit. 
The doctor told my wife to "call the family", but somehow that wasn't
needed.

Is that related to my early experiences with fumes?  Who can say?  I don't
know.  But I do know I wish that I had been more careful.


Tom

Subject: Re: More about the PIPE BOMB
From: glhurst@onr.com (Gerald L. Hurst)
Date: Oct 24 1996
Newsgroups: rec.pyrotechnics,alt.engr.explosives

In article <326F7FBE.1DDA@mania.com>, HK <pyro@mania.com> says:

>I make it by mixing nitric and sulfuric acid, soaking some pure cotton
>in it for a few minutes, then washing it many times in plain water. I
>dry it in my oven using a temperature of roughly 50 'C. I haven't tested
>it with litmus-paper.. maybe that might be a good idea also.

This has got to be a troll. Nobody can possibly be foolish enough to 
dry NC, especially unneutralized  material, in their oven.  This is a 
spectacular way to commit suicide.  NC burns fast enough to turn the 
oven into a cubical pipe bomb and the acid left in the material should
help guarantee ignition.

>By the way, as I was making the NC in our kitchen the other day, when I
>mixed the acids some stinging fumes started to fill the air. What is the
>gas?? I had to go out to breathe, then come in again, do some work for
>20 seconds and go out and breathe again. Why did the mixture heat? The
>sulfuric acid was 97%, while the nitric was 60%. I poured the nitric
>into the sulfuric.. should I do it the other way round? The instructions
>I had said I sould do it just the way I did.

OK, this post is a troll -- at least I hope so.  If you get fumes off
a nitrating mixture, they are probably nitrogen oxides.  In such case, if
what this anonymous author says is true, he has probably already severly
damaged his lungs and could potentially die as a result.  No joke. These
fumes can cause insidious pulmonary edema.  You notice little at first
but later you develop pneumonia-like symptoms and .....  The feeling
on inhalation is more like that of suffocation than stinging in my 
unfortunate personal experience, but I suppose that is a subjective
and possibly language-dependent observation.

Anyway kids, do not try to follow in the alleged footsteps of our 
anonymous and apparently suicidal poster. 

Jerry (Ico)