HDTenEightyP/NetNews huggingface dataset:
From: lamunyj@jacobs.CS.ORST.EDU (James Lamunyon)
Newsgroups: sci.chem,rec.scuba
Subject: Re: Question on partial pressure of O_2 and combustion
Date: 31 Aug 92 20:37:34 GMT
Article-I.D.: leela.1992Aug31.203734.3717
Organization: Computer Science Outreach Services - Oregon State University

In article <STNGIAM.92Aug29155521@e40-008-11.mit.edu> stngiam@athena.mit.edu (Shih-Tung Ngiam) writes:
>
>> If the final mixture is safe as far as spontaneous combustion from
>> hydrocarbon residues go is it safe at the point that you have pure
>> O_2 at a lower partial pressure, i.e. does the nitrogen somehow
>> inhibit combustion? Or is there some other mechanism at work here?
> 
>  Not necessarily. Yes. Maybe.
>
>  Adding air dilutes the hydrocarbon/oxygen mixture with nitrogen.  This
>makes it harder for a self-sustaining chain reaction (e.g. a fire) to
>take place.  Energy that could be used to initiate hydrocarbon
>oxidations essentially gets wasted heating up inert nitrogen molecules.
>
>  At the same pressure, therefore, pure O2 would be more dangerous than
>40% O2.  But your pure O2 system is at a lower pressure.  My first guess
>would be that that makes the mixture less flammable. BUT the lower
>pressure might make the hydrocarbons (i.e., oil and grease) more
>volatile and therefore EASIER to ignite.
>
>  Flame chemistry is quite complex.  Partial pressure is definitely not
>the only factor to consider.  I would advise playing it safe.
>
>  For the H2/O2 mixture - the reason that it does not burn is that there
>is not enough oxygen to sustain the reaction.  

	Most Physcal Chemistry textbooks deal with this sort of a problem,
including several good texts on thermodynamics.  Unfortunatelly the math
will be a problem for some people.  A very good book that deals with this
topic is:

	Engines, Energy, and Entropy  by John B. Fenn  
	copywrite 1982, W.H. Freeman and Company 

It is designed for the "pre-thermodynamics" student who wishes a bit of
an introduction.  Most college libraries probably have it or a similar text.
Its library of congress number is TJ265.F37.   It is fairly easy reading
and assumes you have had at a basic chemistry course and some math skills.

-James LaMunyon
Newsgroups: sci.chem
From: pbays@bach.helios.nd.edu (phil bays)
Subject: Sparkles in the air 
Way: when the hot concentrated methanol solution of 
Organization: Saint Mary's College, Notre Dame
Distribution: sci.chem
Date: Thu, 3 Sep 1992 13:55:32 GMT



Newsgroups: sci.chem
From: cfthb@ux1.cts.eiu.edu (Howard Black)
Subject: Re: Azide Chemistry
Date: Mon, 31 Aug 1992 15:08:30 GMT
Organization: Eastern Illinois University

In article <Btp61s.Ky8@chinet.chi.il.us> saj@chinet.chi.il.us (Stephen Jacobs) writes:

   [responding to a question on ethidium bromide]

>I've never seen this one before, and I'd be reluctant to try it, but what's
>going on is clear.  The primary amine is being diazotized.  Being aliphatic,
>it promptly decomposes to the carbonium ion; being benzylic (and that is
>important here) it lasts long enough to react with something external--in
>this case, to combine with the azide ions in the solution.  Neat, in a way.

    Except that the amine in question isn't primary; it's aromatic.  The
original poster described it as "alpha to an aromatic ring", which was a

>
>But hydrazoic acid is volatile, explosive, lethal in concentrations
>comparable to the concentrations at which HCN is lethal, and causes distress-
>ing circulatory problems (including monumental headaches) at low concentrations.

    But the hydrazoic acid is being formed in situ from the salt and the
HCl, and is consumed as it's formed.  What you say about hydrazoic acid is
true, but there's not much of it around.  Diazomethane is used in much the
same way, and it's pretty nasty stuff, but it's still used very commonly
with an amazingly good safety record.

>I just wouldn't want to do it this way.  Could you maybe displace a benzylic
>chloride or tosylate with azide in DMSO or liquid ammonia?  Not totally safe
>either, but it scares me a lot less.

    Of course, these methods wouldn't work on an aromatic amine.
-- 
   ******************************************************************
     Howard Black                             cfthb@ux1.cts.eiu.edu
     Department of Chemistry                  Eastern Illinois Univ.
Newsgroups: sci.chem
Subject: Re: STN Express Usage?
From: Sue Jones <RBRSEJ@rohvm1.rohmhaas.com>
Date: Wed, 26 Aug 1992 11:20:25 EDT
Organization: Rohm and Haas Company

Re: using STN Express over telnet

I haven't tried using STN Express over the Internet, but have successfully
searched STN (non-graphics mode) using other software on the Internet
(Clarkson's TCP/IP software).I recently posted to some of the library
listservs asking what other people use to do their searching (Dialog, STN,
NLM) over the Internet, and most peopleused some sort of searching
software(primarily Crosstalk and Procomm).  This is apparently possible
because these software packages allow for Interrupt 14 to be selected as
your communications port.  We're just looking into this, so I'm not too sure
about the details.  For more information, check with your local network guru
- that's what we're doing.

Sue Jones
Rohm & Haas
Bristol Information Services
Xref: sparky sci.chem:3379 rec.autos:21363 rec.autos.tech:12153 misc.consumers:16081 sci.environment:11036 talk.environment:3539
From: cec35848@uxa.cso.uiuc.edu (Chuck Carroll)
Newsgroups: sci.chem,rec.autos,rec.autos.tech,misc.consumers,sci.environment,talk.environment
Subject: Re: Carburetors, gasoline, and why I don't recycle
Date: 3 Sep 92 18:06:45 GMT
Article-I.D.: news.Bu0KzB.6w1
Distribution: na
Organization: University of Illinois at Urbana

knapp@spot.Colorado.EDU (David Knapp) writes:

>In article <Btz7xq.H47@news.cso.uiuc.edu> cec35848@uxa.cso.uiuc.edu (Chuck Carroll) writes:
>>1)  You'll need a pretty good estimate of friction, since without it
>>it would take no energy to move a car over level ground. 


>What about W=F*d?  Ek=1/2m*(dV)^2?  P=m(dV)?

Without friction, it would take only an infintesimally small force to
start the car moving, and once you did, it could go indefinitely.  The
same goes for the other equations.

-- 
Chuck Carroll		  | "What can I say when I've ruined your day
cec35848@uxa.cso.uiuc.edu |  And made you all angry and surly?
			  |  How could I make such a thoughtless mistake
			  |  And bury your mother too early?" -- Earl Sinclair
Newsgroups: sci.chem
From: tony2@prefect.uucp (21131-gozdz)
Subject: Re: HELP : Slurries
Organization: Bellcore, Livingston, NJ
Date: Thu, 3 Sep 92 15:46:35 GMT

In article <MARA.92Sep3150922@kauri.vuw.ac.nz> mara@vuw.ac.nz (Mara) writes:
>
>
>Hello. I am a chemistry undergraduate student doing work in my study break   
>involving preparation of slurries from raw sources and then investigation of 
>the drying of these.  
>	As you might guess, preliminary determination of the % solids in each
>slurry is carried out by oven drying weighed samples and calculating
>appropriate differences.  Easy enough.
>	My problem is, although the calculated % solids in the slurries
>are agreeing (to within 0.4% of the total), when I tried to make up further 
>stock slurry with all the dried material left over from the determinations and
>the corresponding, calculated amount of water, the resulting mixture was of
>a completely diffferent consistency (thicker, if that is relevant).
>
>	My calculations are all in order, and the double-check drying I set
>up yesterday indicates that my initial % solids was correct.
>
>	What can have happened? Even if the solid matter _was_ changed in 
>the process of oven drying, it is the same state that I am working from
>in each case.
>
>	Miraculous suggestions and answers gratefully received :)
>
>Amy Gale
>mara@kauri.vuw.ac.nz
>
> 
Well, if you take dried grapes (a.k.a. raisins) and
soak them in warm water, will you get your green or
blue grapes back? Things change tremendously even in
the unanimated kingdom once the water of hydration is
removed (irreversible coagulation comes to mind, where
interparticle forces of various kinds are stronger than
the energy of rehydration).

Tony
Xref: sparky sci.chem:3211 sci.engr.chem:435
From: ckp@netcom.com (Charles Pooley)
Newsgroups: sci.chem,sci.engr.chem
Subject: Re: Liquid fullerenes??
Summary: Liquid fullerene--someone noticed!
Date: 25 Aug 92 16:41:28 GMT
Article-I.D.: netcom.#wan6am.ckp
Followup-To: sci.chem, sci.engr.chem
Organization: Netcom - Online Communication Services  (408 241-9760 guest)

In article <1992Aug25.075458.14303@hippo.ru.ac.za>, robin@ruchem.ru.ac.za writes:
> I/ve also wondered about this, and I suspect that BF is like CO2 and would
> only exist as a liquid under hyperbaric pressures, since intermolecular
> attractive forces (Van der Waals) would be small due to very low polaris-
> ability. On a different tack, what about the He triple point, where in
> the He phase diagram is it? He forms a superfluid, from which energy can't
> be extracted; does it not then have a triple point at all?

Finally my question was understood and noticed.  Now, I don't believe
there's been any conspiracy of silence on the subject, but it has been
very odd that after all this attention to a new family of chemicals,
such a basic set of properties as melting point, vapor pressure, etc has
not yet been reported.  Fullerenes are now being made in ample quantities
for making such determinations.

Now, as to above message--yes, it could be that the t.p. pressure could be
higher than 1 atm, like CO2, which is about 5 bar.   My point is that,
except for helium (which, alone has the superfluid state and liquid state
at absolute zero), all substances which do not decompose on heating, have
a liquifying temperature, and some triple point pressure.

If fullerene is heated under argon or helium at 1 bar, it will either
melt, decompose, or evaporate.  Guessing that the t.p. pressure is
less than 1 bar is a good starting point, as most substances have low
t.p., and 1 bar is convenient starting point.  C60 etc is reported to
be 'very stable', so I would not expect it to decompose below several
thousand kelvins.

On the way to doing this, actual experimental determinations of vapor
pressure vs temperature can be made, and would be worthwhile information
for anyone wanting to handle, produce, melt, make alloys, etc of these
molecular substances (which are not carbon. but hydrogenless hydrocarbons).

Why hasn't this been done and reported???

I/ve been serching for a while (and was main cause of my seeking Internet
access), but no mention....

I'm very puzzled by this.  Has anyone heard of melting of fullerenes?

Please post here, or Email me, or both...

-- 
Charles Pooley                  ckp@netcom.com    GEnie  c.pooley
EE consultant, Los Angeles, CA
From: johnu@syma.sussex.ac.uk (John E. Upham)
Newsgroups: sci.chem
Subject: QCPE 584 : GEOMOS
Keywords: qcpe, geomos, scf
Date: 21 Aug 92 11:34:38 GMT
Organization: University of Sussex


Is there anyone out there brave enough to admit using the GEOMOS
program ? Pleas reply to me directly.

john upham

John Upham, School of Chemistry, University of Reading, Berks., RG6 2AD, UK.
Email: scsupham%susssys1.rdg.ac.uk@uk.ac (BITnet), scsupham@rdg.susssys1 (Janet)
Voice:   +44 734 875123 x7441 (day), Fax: +44 734 311610

-- 
John Upham, School of Chemistry, University of Reading, Berks., RG6 2AD, UK.
Email: scsupham%susssys1.rdg.ac.uk@uk.ac (BITnet), scsupham@rdg.susssys1 (Janet)
Voice:   +44 734 875123 x7441 (day), Fax: +rs
hors: trosa
Newsgroups: sci.chem
From: ANDERSONC@kcgl1.eng.ohio-state.edu (Chris Anderson)
Subject: Re: the TRUTH about Methylene Chloride
Organization: The Ohio State University
Date: Thu, 27 Aug 1992 06:17:56 GMT

Allison Chaiken asks a good question:  what other toxic chemicals do
cosmetics contain?

In OHIO on November 3rd, voters will be able to cast votes for the
right to know when they're being exposed to chemicals that are known
to cause cancer or birth/reproductive defects.  The proposal is issue
5 on the ballot and was placed there by OHIO TOXIC ACTION which is
a project of the consumer group OHIO CITIZEN ACTION.

The law deals with 458 known carcinogenic/mutagenic chemicals and only
requires warnings on products that pose a significant risk.  A very
similar law was enacted in CALIFORNIA in 1986 as PROPOSITION 65.

--
Chris Anderson
Laser Spectroscopy Facility, The Ohio State University
*
Intellectuals solve problems, geniuses prevent them. -- Einstein
Newsgroups: sci.chem
From: cabku01@mailserv.zdv.uni-tuebingen.de (Hartwig Kuehbauch)
Subject: Re: 1,4-dichloro-2-butyne
Organization: Comp. Center (ZDV) U of Tuebingen, FRG
Date: Thu, 3 Sep 1992 08:13:43 GMT

In <1992Sep3.032555.3246@mnemosyne.cs.du.edu> aankrom@nyx.cs.du.edu (Anthony Ankrom) writes:


> I need to know a facile synthesis for 1,4-dichloro-2-butyne. Please post
>or e-mail...

>St. Anthony

Hi Anthony!

Well that's easy. This kind of substance is prepared by the reaction of
2-Butyne-1,4-diol with thionylchloride (A.W. Johnson, J.Chem.Soc. (1946) 1009.)

2-Butyne-1,4-diol (100 g) was dissolved in dry pyridine (170 ml) and thionyl-
chloride (201 ml) was added dropwise during 6 hours with stirring and cooling,
the temperature being kept between 10 and 20 Grad Celsius. The mixture was 
allowed to warm to room temperature, stirred overnight, and treated with
crushed ice.The product was extracted with ether (3x 200 ml) and the combined
extracts were washed with sodiumbicarbonate solution, dried and fractionated
to give 1,4-Dichloro-2-butyne (118.7 g; 83 %) as a colourless oil, b.p.
68-69 Grad Celsius at 17 mm. (165-166 Grad Celsius at 760 mm, slight decomp.).

Warning: 1,4-Dichloro-2-butyne is a vesicant and a weak lachrymator.

Hope I helped you. Bye.

Hartwig


--
=============================================================================
= Hartwig Kuehbauch - University of Tuebingen - Dep. of Inorg. Chemistry II =
= (cabku01@mailserv.zdv.uni-tuebingen.de)     - Germany -                   =
=============================================================================
From: James_J_Kowalczyk@cup.portal.com
Newsgroups: sci.chem
Subject: Re: Alcohol derivitization (adding 3,5-Dinitrobenzoate)
Date: Wed, 26 Aug 92 20:44:49 PDT
Organization: The Portal System (TM)
Distribution: na

grayson@hougen.seas.ucla.edu (David A. Grayson) writes:

>I am trying to derivatize the hydroxyl group of 1-tetralol (not a true
...
>1-tetralol is 1,2,3,4 -tetrahydronaphthol. I use methylene chloride
...
>The reaction takes place in pyridine.
                             ^^^^^^^^
>I use 30 ml pyridine with 0.5 g of 3,5-Dinitrobenzoyl chloride (DNB-Cl) and
>add ~ 1 ml of the 1-tetralol/methylene chloride solution to it. Heat this
>mixture (w/stirring) to 60 C for 15 minutes.
>
>Here is my problem. I can't get this heated solution to pH 2.5. I get down to
>about 4.8 and then nothing. Does anyone see a likely suspect as my acid
>sink? I wouldn't worry about it, but I am adding so much HCl, that I seem
>to be forming some sort of floating ppt.. 
>
>I know about the problems of pHing an organic solution, but by the time I 
>finally gave up the last time. I had gone from ~30 mL organic to ~80mL 
>total volume. Greater than 2% aqueous solution (50 mL of HCl ~60%) should be 
>enough to let any pH meter work. The 50 mL of HCl added were done as follows
>10 mL 1N HCl, 30 mL 5N HCl, and then 10 mL concentrated HCl. 
...
>thanks for any and all help
>
>dave
>--
>UCLA, Dept. Chem. Eng., 5805 Boelter Hall, LA, CA 90024
>David A. Grayson                  grayson@seas.ucla.edu

You begin with 0.37 Mol of pyridine, you add 0.26 Mol of HCl:
you have not protonated all of the pyridine.  You have made
a buffered solution. Add more HCl. 
(The HCl generated from the DNB-Cl is only 0.002 Mol.)

Jim Kowalczyk               James_J_Kowalczyk@cup.portal.com
Eisai Research Institute
From: bjgaed@bb1t.monsanto.com
Newsgroups: sci.chem
Subject: Methyl Chloride
Date: 1 Sep 92 07:58:31 CST
Organization: Monsanto Company, St. Louis, MO

In article <BtvLrv.Mzr@news.cso.uiuc.edu>, dexter@aries.scs.uiuc.edu (Annette Dexter) writes:
> 	As a sideline to the discussion on methyl chloride/methylene chloride,
> the former chemical is made by a number of species of algae, particularly
> red algae, and some plants growing in saline desert soils.  The enzyme in
> question is termed methyl chloride transferase, and appears to play a role
> in helping these plants cope with high levels of sodium chloride in their
> environments.
> 
> 	The estimated biogenic production of methyl chloride is, I believe,
> on the order of 10^9 tons per annum.
> 
> 	Annette Dexter

I didn't know that!

Any idea as to its environmental fate?  Does it hydrolyze to methanol 
or undergo oxidation?  I just checked on its toxicity, lethal 
concentration for rats is 3146 ppm in air, considerably less than for 
methyl bromide (514 ppm).  (Merck Index, 11th Ed.).  Listed as a 
"local anesthetic"!

-- 
--Electric Monk            (Bruce Gaede); 
                            e-mail: bjgaed@ccmail.monsanto.com

"...and then time started seriously to pass."
--Douglas Adams, _Dirk Gently's Holistic Detective Agency_
Newsgroups: sci.chem,rec.autos,rec.autos.tech,misc.consumers,sci.environment,talk.environment
From: knapp@spot.Colorado.EDU (David Knapp)
Subject: Re: Carburetors, gasoline, and why I don't recycle
Organization: University of Colorado, Boulder
Distribution: na
Date: Fri, 4 Sep 1992 03:22:33 GMT

In article <Bu0KzB.6w1@news.cso.uiuc.edu> cec35848@uxa.cso.uiuc.edu (Chuck Carroll) writes:
>knapp@spot.Colorado.EDU (David Knapp) writes:
>
>>In article <Btz7xq.H47@news.cso.uiuc.edu> cec35848@uxa.cso.uiuc.edu (Chuck Carroll) writes:
>>>1)  You'll need a pretty good estimate of friction, since without it
>>>it would take no energy to move a car over level ground. 
>
>
>>What about W=F*d?  Ek=1/2m*(dV)^2?  P=m(dV)?
>
>Without friction, it would take only an infintesimally small force to
>start the car moving, and once you did, it could go indefinitely.  The
>same goes for the other equations.

Yes! (although it would be moving infintessimally slow.) Your integrated 
work in moving it would be the kinetic energy the car now has due to motion.



-- 
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   knapp@spot.colorado.edu
Newsgroups: sci.chem
From: mvp@hsv3.lsil.com (Mike Van Pelt)
Subject: Re: the TRUTH about Methylene Chloride
Organization: LSI Logic/Headland Technology
Date: Fri, 28 Aug 1992 21:47:43 GMT

In article <BtnBF7.79y@chinet.chi.il.us> saj@chinet.chi.il.us (Stephen Jacobs) writes:
>In article <1992Aug27.061756.6719@magnus.acs.ohio-state.edu> ANDERSONC@kcgl1.eng.ohio-state.edu (Chris Anderson) writes:
>>A very similar law was enacted in CALIFORNIA in 1986 as PROPOSITION 65.
>Last I heard, California regulators were starting to get kinda nervous about
>a court decision that the law meant exactly what it said,

That could get scary... Prop. 65 also literally makes it against the
law for anyone in a company with more than 10 employees to flush
the toilet.  Chlorinated water reacts with organics to produce
chloroform, which is on the list.

Who was it that said that the best way to get a bad law repealed
was to literally and rigorously enforce it?
-- 
Mike Van Pelt          | What happens if a big asteroid hits Earth?
LSI Logic/Headland     | Judging from realistic simulations involving a
mvp@hsv3.lsil.com      | sledge hammer and a common laboratory frog, we
sun!indetech!hsv3!mvp  | can assume it will be pretty bad. -- Dave Barry
Newsgroups: sci.chem,rec.autos,rec.autos.tech,misc.consumers,sci.environment,talk.environment
From: knapp@spot.Colorado.EDU (David Knapp)
Subject: Re: Carburetors, gasoline, and why I don't recycle
Organization: University of Colorado, Boulder
Distribution: na
Date: Fri, 4 Sep 1992 03:23:59 GMT

In article <dhalliwe.715546595@muskwa.ucs.ualberta.ca> userDHAL@mts.ucs.UAlberta.CA (David Halliwell) writes:
>knapp@spot.Colorado.EDU (David Knapp) writes:
>
>>In article <Btz7xq.H47@news.cso.uiuc.edu> cec35848@uxa.cso.uiuc.edu (Chuck Carroll) writes:
>>>1)  You'll need a pretty good estimate of friction, since without it
>>>it would take no energy to move a car over level ground. 
>
>
>>What about W=F*d?  Ek=1/2m*(dV)^2?  P=m(dV)?
>
>   What about "An object in uniform motion will continue in uniform motion 
>unless acted upon by a force"? The only energy required would be that used
>to accelerate the car to a given speed. After that, the car will keep
>going in a straight line (over level ground) indefinitely. Unless, of
>course, there is some force acting upon it to slow it down.

Right, but the original poster did not metion the energy required to 
initiate motion, which is rather important, right?

-- 
David Knapp                                      University of Colorado, Boulder
Perpetual Student                                   knapp@spot.colorado.edu
Xref: sparky sci.chem:3283 sci.physics:13753
From: johnu@syma.sussex.ac.uk (John E. Upham)
Newsgroups: sci.chem,sci.physics
Subject: INDO/Zerner's INDO calculations
Keywords: INDO, Zerner, molybdenum, QCPE, GEOMOS.
Date: 21 Aug 92 11:31:39 GMT
Organization: University of Sussex

I'm looking for code for Zerner's INDO program including parameters
for molybdenum. I am presently using the QCPE program no. 584 called
GEOMOS but this is devoid of parameters for 2nd row transition
metals. 

Please mail me at Reading Univ direct.

 
john upham

John Upham, School of Chemistry, University of Reading, Berks., RG6 2AD, UK.
Email: scsupham%susssys1.rdg.ac.uk@uk.ac (BITnet), scsupham@rdg.susssys1 (Janet)
Voice:   +44 734 875123 x7441 (day), Fax: +44 734 311610

-- 
John Upham, School of Chemistry, University of Reading, Berks., RG6 2AD, UK.
Email: scsupham%susssys1.rdg.ac.uk@uk.ac (BITnet), scsupham@rdg.susssys1 (Janet)
Voice:   +44 734 875123 x7441 (day), Fax: +44 734 311610
Newsgroups: sci.chem
From: cfthb@ux1.cts.eiu.edu (Howard Black)
Subject: Re: the TRUTH about Methylene Chloride
Date: Thu, 27 Aug 1992 15:11:15 GMT
Organization: Eastern Illinois University

In article <27AUG199208344445@phobos.ucc.umass.edu> s9874194@phobos.ucc.umass.edu (s9874194) writes:

  [in response to a posting about pending Ohio legislation that would
mandate the listing of known carcinogens in consumer products]

>Do you know what NMR is? Nuclear Magnetic Resonance. Then, what is MRI?
>Magnetic Resonance Imagine. Are they different? In princinple, they are
>not. Then why they differ in names? If you are a doctor in a hospital
>and you tell your patient to do a NUCLEAR ...., s/he would suspect that
>you are going to *Nuke* her/him. Public fear about chemistry or I should
>say science, has gone too far. I suspect that religion is playing a role
>here.

    Would you clarify what this has to do with the posting to which you are
responding?  I am particularly interested in the religious connection.

    BTW, it's "Imaging", not "Imagine".

-- 
   ******************************************************************
     Howard Black                             cfthb@ux1.cts.eiu.edu
     Department of Chemistry                  Eastern Illinois Univ. 
Newsgroups: sci.chem
From: nowsa%Solomon.Technet.sg (shan wong)
Subject: Conductive Polyethylene
Organization: National University of Singapore
X-Newsreader: Tin 1.1 PL5
Date: Thu, 3 Sep 1992 01:12:29 GMT



Newsgroups: sci.chem,comp.text.tex