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From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel )
Subject: Re: Uses for Mercury
Message-ID: <1994May19.161640.1490@ringer.cs.utsa.edu>
Date: Thu, 19 May 1994 16:16:40 GMT
In article <1994May19.050052.85060@ns.cc.lehigh.edu> mal2@ns.cc.lehigh.edu (MAX A LUPTON) writes:
>In article <1994May18.092300.29464@walter.cray.com>, swilhelm@cheshire.cray.com
>(Suzanne C. Wilhelm) writes:
>>My finace asked me to post this for him:
>>
>>1. He has a jar of mercury in his basement and would like to know of
>> some of the ways that mercury is used in pyrotechnics.
>
>The most common use of Hg in pytotechnics that I am aware of is in the
>preparation of "mercury fulminate" or, to us chemistry types, mercury
>isocyanate. I believe that this used to be a common component of primers
>for ammunition at one time (pre 1950's I think), but the salts formed by the
>detonation of this compound are hygroscopic (they absorb water from the
>air) and after shooting these corrosive salts would attract water, and salt
>water is almost as damaging to gus as the current political administration :-).
[ deleted for brevity ]
Max,
Where did you get the idea that mercury fulminate and mercury isocyanate
are even related compounds? Although they contain the same atoms,
fulminates and isocyanates are as different as ethyl alcohol and methyl
ether (same atoms there, too). If there is a textbook that makes this
claim, I'd like to know so I can send nastygrams to the publisher!
Fulminates are salts of the (hypothetical) fulminic acid, which can be
thought of as the oxime of carbon monoxide. In particular, they contain a
carbon atom with only a sextet of electrons, so they tend to be a bit
unstable:
H-O-N=C: <-- Fulminic acid (Hypothetical)
:C=N-O-Hg-O-N-C: <-- Mercury fulminate (Goes bang)
Isocyanates are salts of the completely isolable isocyanic acid. All of
the atoms have octets of electrons (except hydrogen, of course), and the
salts are entirely stable compounds:
H-N=C=O <-- Isocyanic acid (Isolable)
O=C=N-Hg-N=C=O <-- Mercury isocyanate (Stable)
One other piece of information. Mercury fulminate is not particularly
corrosive to gun barrels, though it renders the brass cartridge case
brittle and not reusable. "Corrosive" primers contain potassium chlorate.
Note that when mercury fulminate detonates, it does not produce much of a
flame. If you have ever heated any to detonation, you will know that
there is not much flash involved (lots of noise, though!) Well, in order
to ignite gunpowder, you need a flame, not a bang. So the primers are
compounded using mercury fulminate, rosin, and potassium chlorate. The
mixture makes for a hot flame, and as an afterthought, stuff like
potassium chloride. Which, as you assert, is NASTY on gun barrels. Back
in the days when the propellant was black powder, it didn't make a
difference.
------------------------------------------------------------------------
Norman L. Reitzel, Jr. | "When you live beside the graveyard,
nreitzel@lonestar.utsa.edu | you can't cry for every funeral."
Blue Water Ventures, dba. | Russian Proverb
------------------------------------------------------------------------
Newsgroups: rec.pyrotechnics
From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel )
Subject: Re: Uses for Mercury
Message-ID: <1994May23.214057.18991@ringer.cs.utsa.edu>
Date: Mon, 23 May 1994 21:40:57 GMT
In article <iTQtjaE96Z2H063yn@world.std.com> moroney@world.std.com (Michael Moroney) writes:
>In article <1994May19.161640.1490@ringer.cs.utsa.edu>, Norman L. Reitzel wrote:
>>
>> Fulminates are salts of the (hypothetical) fulminic acid, which can be
>> thought of as the oxime of carbon monoxide. In particular, they contain a
>> carbon atom with only a sextet of electrons, so they tend to be a bit
>> unstable:
>>
>> H-O-N=C: <-- Fulminic acid (Hypothetical)
>>
>> :C=N-O-Hg-O-N-C: <-- Mercury fulminate (Goes bang)
>>
>> Isocyanates are salts of the completely isolable isocyanic acid. All of
>> the atoms have octets of electrons (except hydrogen, of course), and the
>> salts are entirely stable compounds:
>>
>> H-N=C=O <-- Isocyanic acid (Isolable)
>>
>> O=C=N-Hg-N=C=O <-- Mercury isocyanate (Stable)
>
>Err, what you describe as isocyanate is cyanate (without the iso- prefix).
>Fulminates are sometimes referred to isocyanates correctly. The iso-
>prefix (in chemistry) means a molecule or group that has the same atoms
>as another molecule/group with the same name (without the iso- prefix)
>but with the atoms rearranged. Fulminates(isocyanates) and cyanates are
>one example, as are propyl alcohol and isopropyl alcohol. The iso-
>prefix isn't used much anymore, since it can be ambiguous (which of the
>4 butyl alcohols is "isobutyl alcohol"?) and IUPAC naming describes the
>molecule exactly.
>
>-Mike
No, No, No....
You had me going for a second, so I checked Merck, and Vollhardt, and
Morrisson, and CRC, and everybody agrees:
Cyanates are this:
H-O-C=N <--- Couldn't show C-N triple bond
isoCyanates are
H-N=C=O
and Fulminates are
H-O-N=C:
ONLY the fulminate has carbon with a sextet of electrons. The other ions
all have fully satisfied octets, though they have some resonance forms
that have separation of formal charges.
------------------------------------------------------------------------
Norman L. Reitzel, Jr. | "When you live beside the graveyard,
nreitzel@lonestar.utsa.edu | you can't cry for every funeral."
Blue Water Ventures, dba. | Russian Proverb
------------------------------------------------------------------------
Newsgroups: rec.pyrotechnics
From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel )
Subject: Re: Uses for Mercury
Message-ID: <1994May23.224444.20575@ringer.cs.utsa.edu>
Date: Mon, 23 May 1994 22:44:44 GMT
In article <1994May23.214057.18991@ringer.cs.utsa.edu> nreitzel@lonestar.utsa.edu (Norman L. Reitzel ) writes:
>
>Cyanates are this:
>
> H-O-C=N <--- Couldn't show C-N triple bond
>
>isoCyanates are
>
> H-N=C=O
>
>and Fulminates are
>
> H-O-N=C:
The "iso" prefix refers to the same atoms rearranged, but how much you can
rearrange them is something else again. Otherwise, dimethyl ether,
2-oxapropane, would be called iso-ethyl alcohol, and it is NEVER referred
to in that manner. Calling a fulminate an "iso-cyanate" is a real
stretch, considering that cyanates and isocyanates have similer chemistry
and are (through cyanic acid <--> isocyanic acid in aqueous solution)
somewhat interconvertable.
Fulminic acid, on the other hand, does not exist in the free state, at
least anywhere near ambient temperatures. Also, it is isoelectronic
(another iso) with diazomethane, and not with ketene or allene, as are
cyanic acid and isocyanic acid. It's not even an isomer in the general
sense, as the atoms are not only rearranged, they have different oxidation
states.
Just to add some more confusion to this subject, there is a commercial
product called mercury oxycyanide. This is a mixture of mercuric oxide
(yellow) and mercuric cyanide. I believe it is prepared by precipitating
mercury with basic cyanide solution (containing free OH- ions). It is
unstable when the cyanide content approches stoichiometric amounts, and
can detonate. This substance, which is a mixture, does not contain
cyanate, isocyanate, -or- fulminate!
------------------------------------------------------------------------
Norman L. Reitzel, Jr. | "When you live beside the graveyard,
nreitzel@lonestar.utsa.edu | you can't cry for every funeral."
Blue Water Ventures, dba. | Russian Proverb
------------------------------------------------------------------------
Newsgroups: rec.pyrotechnics
From: nreitzel@lonestar.utsa.edu (Norman L. Reitzel )
Subject: Re: Uses for Mercury
Message-ID: <1994May20.154204.27036@ringer.cs.utsa.edu>
Date: Fri, 20 May 1994 15:42:04 GMT
In article <2rhvo5$5396@ns1.CC.Lehigh.EDU> mal2@ns1.CC.Lehigh.EDU (MAX A LUPTON) writes:
>In article <1994May19.161640.1490@ringer.cs.utsa.edu>, nreitzel@lonestar.utsa.ed
>u (Norman L. Reitzel ) writes:
>>In article <1994May19.050052.85060@ns.cc.lehigh.edu> mal2@ns.cc.lehigh.edu (MAX
> A LUPTON) writes:
>>
>> [ deleted for brevity ]
>>
>>Max,
>>
>>Where did you get the idea that mercury fulminate and mercury isocyanate
>>are even related compounds? Although they contain the same atoms,
>>fulminates and isocyanates are as different as ethyl alcohol and methyl
>>ether (same atoms there, too). If there is a textbook that makes this
>>claim, I'd like to know so I can send nastygrams to the publisher!
>
> Well, to show that I am not a complete idiot (and to reassure my employers
>that they are not wasting their money paying me as a chemist) I will give
>you my reference for this apparently inaccurate statement.
>
> "Chemistry, The Elements and Their Reactions" by Eric Hutchinson, Ph.D.
> copywrite 1959 by W.B. Saunders Company
> pg 660, second to last paragraph on the page, I quote
>
> "When mercury is treated with concentrated nitric acid in the presence of
> alcohol a complicated reaction takes place and a white, insoluble compound
> with the formula Hg(ONC)2 separates out. This is mercuric isocyanate,
> which is highly explosive and is used under the name of mercury fulminate
> as a detonator in many types of explosive caps."
>
Max,
I think I owe you an apology - I didn't intend to denigrate your comments
or anything like that. I was pretty sure that your comments had a basis
in print, as I can't see chemists leaping to that particular conclusion
accidentally. I was entirely serious about writing publishers, as modern
textbooks often have such errata, and if people like you or me don't write
snide letters, the errata last edition after edition.
Of course, fixing a 1959 chemistry book might be asking a bit much.
Have you noticed that it seems like the 50's books are a whole bunch
better (as in more interesting, and more facts) than the latest batch of
chemistry texts? I noticed that the last four or five trying to get
approval in Texas for high school chemistry classes are AWFUL. They are
almost guaranteed to take a potential chemist and turn them into a history
major. They are DULL. One of them has a picture of a man in a hazard
suit handling a piece of lead pipe, as though it was radioactive.
Back on the subject of mercury, and of cyanate salts in general, did you
know that mercuric thiocyanate was the chemical used to make Pharoah's
Serpents (snakes) for a long time? Picture all these kiddies, and all
these parents who didn't want their kids messing with "dangerous"
fireworks, all gathered around a couple hundred grams of burning mercury
compounds. Kind of shows two things: Mercury isn't as bad as it's
reputation, and there actually are reasons to regulate stuff like that.
Have a good one!
------------------------------------------------------------------------
Norman L. Reitzel, Jr. | "When you live beside the graveyard,
nreitzel@lonestar.utsa.edu | you can't cry for every funeral."
Blue Water Ventures, dba. | Russian Proverb
------------------------------------------------------------------------
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