HDTenEightyP/NetNews huggingface dataset:
From: dblackbu@alleg.edu (Dave Blackburn)
Newsgroups: sci.chem
Subject: Re: ORBITAL OVERLAP QUESTION
Date: 17 Nov 92 22:40:41 GMT
Organization: Allegheny College

In article <1992Nov13.072209.4228@darwin.ntu.edu.au> b_duke@darwin.ntu.edu.au  
(Brian Duke) writes:
|In article <1992Nov08.194440.38866@ux1.cts.eiu.edu>, cfthb@ux1.cts.eiu.edu  
(Howard Black) writes:
|> In article <17235@mindlink.bc.ca> Gordon_Wong@mindlink.bc.ca (Gordon Wong)  
writes:
|>>I need some confirmation regarding the orbital overlap diagram of the
|>>doubly double-bonded CO2 molecule. The carbon would hybridize to form 2 sp
|>>orbitals and 2 unhybridized p orbitals. Would one sp orbital from the C
|>>atom overlap a p orbital from one O atom to form a sigma bond and the other  
p
|>>orbital from the C atom form a pi bond with the other p orbital from the O
|>>atom, resulting in the double bond?
|>>
|>>I just want to know if this is correct or am I completely off base?
|> 
|>     The latter.  The oxygens are sp2, thus, the sigma bond results from
|> overlap of C(sp)-O(sp2), and the pi bond from C(p)-O(p).  The other two
|> O(sp2) hybrids contain the unshared electron pairs.
|> -- 
|Gordon is not completely off-base, if I follow him correctly. Since
|there are no other atoms attached to the O, we can not argue for 
|hybridisation from the steric arrangement around the O. From this point
|of view sigma C(sp)-O(pz) [let z be axis of molecule.] is just as reasonable
|as sigma C(sp)-O(sp2). The pi bonds of course are C(px)-O(px) on one side,
|and C(py)-O(py) on the other side. The question can be partly answered
|by looking at high level quantum chemical calculations. The anwer is that
|the s orbitals on O are involved in the sigma bond, but not to the full
|extent of sp2, but more of course than the zero involvement of just p.
|
|The answer lies between Gordon and Howard, but in my view closer to 
|Gordon since there is no reason to invoke hybridisation on the O.
|
|I hope this helps to clarify this problem.
|-- 
|                  Brian Salter-Duke (Brian Duke)
|School of Chemistry and Earth Sciences, Northern Territory University
|        GPO Box 40146, Casuarina, NT 0811, Australia.
|Phone 089-466702   FAX 089-410460    E-mail B_DUKE@DARWIN.NTU.EDU.AU

um, hold on. The CO2 molecule has D-infinity-h symmetry, but the above  
descriptions do not. The O must be "sp hybrid", with both px and py orbitals  
involved in the pi MO's. Thus the LCAO/MO treatment says the pi system has all  
3 atoms involved, generating bonding, non-bonding, and anti-bonding MO's of  
which the first two are filled. There are two sets, one derived from the px  
and one from py. (Now, if you'll excuse me, I have a student doing the  
resonance Lewis Dot structures of the isoelectronic NCO- ion.)

--

* Dave Blackburn  dblackbu@alleg.edu  flames to self@home.dev.null *          
* Chemistry, Macs, Hypercard, cats,  <>< religion, & the Dead      *
* (Anyone else who held these opinions would be as crazy as I am.) *
*   "Sometimes the songs that we hear are just songs of our own"   *
Newsgroups: sci.chem
From: lordj@vccsouth13.its.rpi.edu (Joel Patrick Lord)
Subject: Re: Methylene Dichloride
Reply-To: lordj@rpi.edu
Organization: Rensselaer Polytechnic Institute, Troy, NY.
Date: Fri, 20 Nov 1992 05:54:48 GMT

   I meant in paint removers.  It's mixed in with god knows what else
and will remove skin in a matter of seconds.  I've never seen pure
methylene chloride outside of the lab.

Joel Lord (lordj@rpi.edu)
-- 
Sleep is a very valuable commodity.  Unfortunately, you never realize
just how valuable it is, until you can't get any.
Xref: sparky sci.chem:4710 rec.pyrotechnics:3778
From: dmeier@casbah.acns.nwu.edu (Douglas Meier)
Newsgroups: sci.chem,rec.pyrotechnics
Subject: H2O2 Version 2.1
Date: 19 Nov 92 03:59:23 GMT
Article-I.D.: news.1992Nov19.035923.8381
Organization: Northwestern University, Evanston Illinois.

I asked earlier what the reaction was between H2O2 and flesh (i.e. why the
bubbles) and got two responses.  

1)  It breaks down into H20 and O2, with some O radicals reacting with the
skin.

2)  Oxidation reaction where H2O and CO2 are the gases given off.

Now I know that H2O2 can be an oxidizing agent or a reducing agent, dependent
on the conditions, but I don't know which way this reaction occurs under
conditions of H2O2 reacting with organic materials.  

Any more suggestions?



-- 
Douglas C. Meier		|  Spin with the archer now, and       
Northwestern University, ACNS 	|  laugh in his face as he cocks his  
This University is too Commie-	|  bow....  -The Guess Who
Lib Pinko to have these views.	|  dmeier@casbah.acns.nwu.edu
Newsgroups: sci.chem
From: rajat@sunny3.che.clarkson.edu (Rajat Kapoor)
Subject: Motor Oil Disposed Exceeds Exxon Valdez 
Organization: Clarkson University
Date: Wed, 18 Nov 1992 03:36:03 GMT

From article <4861@equinox.unr.edu>, by whitbeck@equinox.unr.edu (Michael Whitbeck):


> I suppose a distinction should be made between commercial oil
> products (e.g. light lube oil) and crude oil. I guess most folk
> assumed you meant crude- most often associated with major spills.

I learnt an eye-opening fact from a science program (or maybe news)
aired over Canadian TV, that the total amount of motor oil disposed off by
Canadians far exceeds Exxon Valdez spill or the one during
Gulf war.

The program also showed shots of shut-down waste-oil recovery units in
dilapidated state - reason : uneconomical to run.

This isn't a Canadian problem, I bet similar figures exist for
many countries.

Kapoor
> 
Newsgroups: sci.chem
From: modowd@lonestar.utsa.edu (Michael T. O'Dowd)
Subject: Help with a subject.
Organization: University of Texas at San Antonio
Date: Wed, 18 Nov 1992 12:00:30 GMT

Greetings all out there. I am a new poster to this group and wanted to know
if there was anyone out there at all that could help me with a chemical.

I would like to know if anyone knows the chemical makeup of 
methylenedioxyamphetamine (MDA) or 3,4-methylenedioxymethamphetamine (MDMA).
If you could inform me of some texts or periodicals where I can find any
information on these (chemical makeup, effects, molecular weights of chemicals,
etc.) I would appreciate it. If you can tell me yourself, I would appreciate
that also. Please send any information to modowd@lonestar.utsa.edu. Thanks

Michael
                        
                          OCH
                          |  3
                          | 
                        /. \___O         This is the MDMA molecule.
                       |   .|  |         I hope that it is readable to you.
                      / \. /\  /         The '.' are more readable |'s.
               H NCHCH        O          My research has left me at a dead
                2 |   2                  end, as I don't know what these
                  |                      chemicals are or do.
                  CH
                    2

               MDMA

-- 

                 If it walks like a duck, it must be a duck.
                  If it barks like a dog, it must be a dog.
                  If it flies and bites, run the fuck away!
From: azit@occuphealth.fi (Antti Zitting)
Newsgroups: sci.chem
Subject: Re: Methylene Dichloride
Date: 20 Nov 1992 22:10:53 +0200
Organization: Institute of Occupational Health, Finland
NNTP-Posting-Host: paja.occuphealth.fi
X-Newsreader: Tin 1.1 PL5

IARC (International Agency for Research on Cancer) has evaluated that
dichloromethane) methylene chloride may be carcinogenic.

//antti
From: gallivan@after (Justin Gallivan)
Newsgroups: sci.chem
Subject: Re: Methylene Dichloride
Date: 19 Nov 92 00:47:03 GMT
Article-I.D.: news.Bxxu6F.A5o
Distribution: sci.chem
Organization: University of Illinois at Urbana

norton@joker.optics.rochester.edu (Scott Norton) writes:


>       Question:  Does anyone know if there is a "popular" name for
>methylene dichloride??  CH2Cl2  ??
>   I was told it was very common and could probably be obtained at a
>hardware store... so is it a paint thinner or something like that??

>Thanx!
>Scott
>
CH2Cl2 is known as methylene chloride or dichloromethane.  It was at one
time used in paint thinners (although I'm not sure to what extent now).
I can't say that I have seen it sold alone in a hardware store though, 
you may wish to look at the ingredients of some of the paint thinners.  

--
Justin Gallivan                Calculus&Mathematica Development Team
gallivan@after.math.uiuc.edu   University of Illinois at Urbana-Champaign
-------------------------------------------------------------------------
"That's CAUCASIAN trash to you, pal" -C.M. Dockstader 8 May, 1992
From: kniaz@sol1.lrsm.upenn.edu (Chris Kniaz -Fischer)
Newsgroups: sci.chem
Subject: Re: Bucky things
Date: 19 Nov 92 23:03:38 GMT
Organization: Laboratory for Research on the Structure of Matter, University of Pennsylvania

In article <sundermm.66.0@columbia.dsu.edu> sundermm@columbia.dsu.edu (MARC SUNDERMEYER) writes:

>    What ever did they accomplish with the Bucky Bunny which didn't spin, is 
>it a basis for the bucky onions perhaps?

According to Rick Smalley (who gave a talk at Penn) carbon chemists
new about onions for a long time (he even showed slides with pictures
from some old papers), they seem to be ultimate form of bucky
tubes. As I remembered someone did some calculations, turns out
onions are very stable...

More interesting are bucky tubes. If you dope them with
Rubidium they give X-ray spectrum similar to graphite-Rb, moreover
they molecural formula is identical to the long known
graphite compound RbC8 and they also squize like graphite intercal.
compound! Why not call them graphite then...
-- 

Krzysztof Kniaz, Penn |If only God would give me some clear sign! 
LRSM ,                |Like making a large deposit in my name at a Swiss bank.
Phila, PA, 19104, USA |               Woody Allen
From: pmartens@reed.edu (Peter Martensen)
Newsgroups: sci.chem
Subject: Re: Need info on rechargable NiCd batteries...
Date: 15 Nov 92 20:33:49 GMT
Organization: Reed College, Portland, OR

In article <1e4etdINNb5g@usenet.INS.CWRU.Edu> an881@cleveland.Freenet.Edu (Dick Middaugh) writes:
>
>Long ago and far away, NiCad batteries had a "memory effect", and
>it was important to discharge them fully before recharging them.
>That is not true of present-day batteries, but the folklore 
>persists.
>-- 
>Compuserve:  71077,1676
>Rocky River, OH  USA

are you sure about this?  my new norelco rechargeable shaver explicitly says
to let the charge fully deplete before recharging. So does my cam-corder, and
i believe that TV stations have special recharging stations for their large
NiCad batteries that drain all the charge before recharging them...

pmartens@reed.edu
Xref: sparky sci.chem:4662 sci.math:15145 sci.physics:19105 sci.bio:4155 misc.education:4361
From: moroney@ramblr.enet.dec.com
Subject: Re: calcium sulfate
Organization: Digital Equipment Corporation
Date: Fri, 20 Nov 1992 02:40:12 GMT

In article <1992Nov19.141153.12639@ncsu.edu>, jrkitchi@eos.ncsu.edu (JOHN ROBERT KITCHIN) writes...
> 
>can calcium sulfate be used as an oxidiser.  If so what is its 
>decomposition temperature? thanks.

Certain pyrotechnic twinkling strobe compositions use a reaction where
strontium or barium sulfate and magnesium react for the 'flash'.  Calcium
sulfate can also be used but doesn't produce a good color.

Also, barium sulfate is reduced with carbon to barium sulfide when recovering
barium from a barium sulfate ore.  I mention strontium and barium sulfate since
they are somewhat similar to calcium sulfate.


-Mike
Newsgroups: sci.chem
From: rajat@sunny1.che.clarkson.edu (Rajat Kapoor,P303,2124)
Subject: Re: Oil Spills
Organization: Clarkson University
Date: Mon, 16 Nov 1992 15:28:25 GMT

From article <74956@hydra.gatech.EDU>, by gtd205a@prism.gatech.EDU (Hody Crouch):
> 
> Well, the method that you suggest cleaned up the vast majority of the spilled
> oil.  The coast guard and other organizations put out large booms and the oil
> was 'skimmed' off the top of the water.

Maybe, at the initial stages of the spill. Oil can quickly spread over to
cover large areas of water, theoretically, perhaps to monolayer
thickness ( volatility of oil and other bulk properties may not
aquatic life.

To this end I recall the terms as "breaking the oil" in the news...


>   1.  Some of the oil reached land, where it coated the shoreline, and any 
> animal on it.  Once on the shore, oil becomes extremely difficult to clean up.
> And even if it is cleaned up, much damage has already been done.

The problem could be mutual pollution of Sand <=> Sea water. Remedy one,
Kapoorer re-pollutes...
From: jtwarden@rpi.edu (Joseph Warden)
Newsgroups: sci.chem
Subject: Re: Heavy water separation
Date: 15 Nov 92 21:29:44 GMT
Article-I.D.: mac4.jtwarden-151192162455
Followup-To: sci.chem
Organization: Chemistry

In article <1992Nov9.023243.20791@isus.UUCP>, hoyt@isus.UUCP (Hoyt A.
Stearns jr.) wrote:
> 
> So maybe it would be feasible to accomodate some bacteria to D20, and use
> them to somehow separate D20, perhaps by extracting the bacteria from soln,
> and pressing.
> 

Growth of bacteria as well as algae in D2O has been carried out
commercially for a number of years. MSD in Quebec markets deuterated
compounds derived from perdeuterated algae. The pioneering studies
in algae by the Argonne group (Katz, Crespi, Daboll..) made such
large scale growth practical. Growth of deuterated algae is not
difficult if one is careful - cultures that I started at the
University of Western Ontario were maintained for years after I
departed.

---------------------------------------------------------------------
Joseph Warden
Department of Chemistry
Rensselaer
Troy, NY 12180-3590
EMail: wardej@rpi.edu or userhay3@rpitsmts (BITNET)
Tel: (518)276-8482
---------------------------------------------------------------------
From: tt@wag.caltech.edu (Toshi Takeuchi)
Newsgroups: sci.chem
Subject: Re: Methylene Dichloride
Date: 20 Nov 1992 18:38:26 GMT
Organization: California Institute of Technology, Pasadena, CA
NNTP-Posting-Host: sgi1.wag.caltech.edu

In article <jpz10q_@rpi.edu> lordj@rpi.edu writes:
(about methylene chloride)

>   I meant in paint removers.  It's mixed in with god knows what else
>and will remove skin in a matter of seconds.  I've never seen pure
>methylene chloride outside of the lab.

No, it doesn't remove skin at all.  It just sort of goes through the skin
and make it dry as someone pointed out.  It also makes the skin tingle
with some sort of pain.

However!!

Don't be stupid and intentionally dip you hand in methylene chloride
to check it out unless you like to eat up your liver...

Toshi
From: frederik@pollux.acs.uci.edu (M. Donald Frederick)
Subject: Reaction-Diffusion
Newsgroups: sci.chem
Reply-To: frederik@pollux.acs.uci.edu (M. Donald Frederick)
Organization: University of California, Irvine
Keywords: Finite-Difference,Numerical Methods
Date: 23 Nov 92 23:49:35 GMT


We are interested in obtaining references and/or source code in Fortran or C
for numerical solutions to Reaction-Diffusion equations in 2 spatial dimensions.
If there is enough interest, I will summarize responses. Thanks.

------------------------------------------------------------------------
        Donald Frederick       |      Office of Academic Computing
        frederik@uci.edu       |      University of California, Irvine
        frederik@UCI.BITNET    |      Irvine, CA  92717
        (714) 725-3200         |      FAX (714) 725-2069
-----------------------------------------------------------------------


Newsgroups: sci.chem
From: rajat@sunny3.che.clarkson.edu (Rajat Kapoor)
Subject: Re: Gold dust a fire hazard?
Organization: Clarkson University
Date: Wed, 18 Nov 1992 16:15:52 GMT

From article <4865@equinox.unr.edu>, by whitbeck@snowlake.math.uh.edu (Mike Whitbeck):
> For the reaction to be thermo allowed one considers the NET change from
> products to
> reactants at the specified reaction conditions.
>                  *****************************    <- shouting for the
> hard of hearing


Your point was made, but seriously, all this while there was a tacit 
understanding that the conditions were 1 atm, 25 deg C...


> 
> The oxidation may be kinetically slow in the absence of an initiator or
> catalyst.
> However small particles are more reactive (re chemical potential) than
> large particles-
> lowering the particle size alters the thermodynamics.
> ****************************************************
> 
> 
> The delta G for the reaction should be the appropriate change 
> in energy for the CONDITIONS-- getting hot enought and having particles
> small enought.
> 
> 	IT IS THE DELTA G FOR THE REACTION UNDER REACTION CONDITIONS THAT COUNTS

Lets hammer this out (flames welcome)

dG = dH - TdS     Now, dH is the heat released, and TdS is the unavailable
energy, i.e., the irrecoverable loss of energy due to, say,
reorganization of bonds, etc.

dG, then, gives a measure of tendency, not heat released.

This brings me back to my original argument (summarized)

For a given dH (metal specific,cond.specific), the heat released
would raise the particle temp globally if heat capacity ( not sp. ht.
cap. ) is low. This rise in T increases the rate, which in turn 
increases the global T faster. The rise in T helps to overcome
diffusional resistance of metal in the interior. All in all, after a
certain temp is reached, the particle burns uniformly.

Remember, we used heat capacity in the argument.  Now heat capacity
is mass dependent, and therefore on particle size, given density.

To conclude, IMHO, all metals have a characteristic critical specific surface
( depending on dH of rxn, and assuming Cp for most metals is near) at which
it will burn, and beyond which it wouldn't matter.


>                                   ********       *******************
> really loud shouting->  	 **********     *********************
> 	                          ********       *******************



Kapoor
From: dsmith@uoft02.utoledo.edu
Newsgroups: sci.chem
Subject: Re: ZPE differences
Date: 15 Nov 92 23:09:40 EST
Organization: University of Toledo, Computer Services

In article <Bxqs5M.GK6@ucunix.san.uc.edu>, pollack@ucunix.san.uc.edu (Steven Pollack) writes:
> 
> By the bye, since XXPAC's are parameterized for heats for formation, is
> the energy including the ZPE or are these energy at the bottom of the
> well?
> 
Steve:
	Recall that the parameters in XXPAC are all for elements in their
standard states at 298 K.  I think that this precludes ZPE from being 
included.  Furthermore, the energy calculated is heat of formation of the
molecule/compound at 298 K relative to those elements, and ZPE is not 
typically included in deltaH(formation).
	Finally, there is a complete but confusingly written section in the
MOPAC 6.0 manual on thermochemistry, which explains how to get standard
entropy, enthalpy and free energy from a THERMO calculation, which requires
some corrections for the fact that all the parameters are for 298 K.

Doug Smith
Assistant Professor of Chemistry
The University of Toledo
Toledo, OH  43606-3390

voice    419-537-2116
fax      419-537-4033
email    dsmith@uoft02.utoledo.edu
Xref: sparky sci.chem:4767 rec.pyrotechnics:3815
From: xenon@drycas.club.cc.cmu.edu
Newsgroups: sci.chem,rec.pyrotechnics
Subject: Re: H2O2 Version 2.1
Date: 21 Nov 92 17:55:35 -0500
Organization: Carnegie Mellon Computer Club

In article <1992Nov19.035923.8381@news.acns.nwu.edu>, dmeier@casbah.acns.nwu.edu (Douglas Meier) writes:
> I asked earlier what the reaction was between H2O2 and flesh (i.e. why the
> bubbles) and got two responses.  
> 
> 1)  It breaks down into H20 and O2, with some O radicals reacting with the
> skin.
> 
> 2)  Oxidation reaction where H2O and CO2 are the gases given off.
> 
> Now I know that H2O2 can be an oxidizing agent or a reducing agent, dependent
> on the conditions, but I don't know which way this reaction occurs under
> conditions of H2O2 reacting with organic materials.  
> 
> Any more suggestions?
> 

Whether H2O2 (or amy substance) acts as an oxidant or a reductant depends on
two things:

1) The reduction potential of H2O2, and

2) The reduction potential of the thing it is reacting with.

See the CRC handbook for a table of reduction potentials.

H2O2 acts as an oxidizing agent when it reacts with organic materials.
  
- x

Newsgroups: sci.chem
From: jmc0580@acfcluster.nyu.edu
Subject: ANSWER TO: Where can we buy C60?
Organization: New York University
Date: Sun, 22 Nov 1992 06:57:43 GMT

Hi netters!

	A couple of days ago I requested some information about
where to buy C60. Yesterday I received the following information
from Gerd Rosenblatt about C60 and C70 sources, from Lev Sidorov
at Moscow State University. Hope this can help.

	Thanks again to Gerd Rosenblatt.

                               
				Jesus M. Castagnetto
				Department of Chemistry
				New York University
                                jmc0580@acfcluster.nyu.edu
				==========================

>> START OF INCLUDED MESSAGE

*STUFF DELETED*
From: grosenblatt@Csa3.LBL.Gov (Gerd M Rosenblatt)
*STUFF DELETED*

Dear colleague,
        I just received the following message from Lev Sidorov
at Moscow State University.  They produce C60 and C70 and are looking
for customers.  If you know of potential interest, please send me
a note or contact Sidorov directly.
        Thanks very much for your help.
                Best wishes,
                Gerd Rosenblatt

----- Start of forwarded message[s] -----
From: sidorov@mch.chem.msu.su (Chemistry Dept., MSU)
Date: Tue, 20 Oct 1992 14:03:07 MSD
Subject: Letter to Rosenblatt
*STUFF DELETED*

Dear Gerd, *STUFF DELETED* We produce fullerenes C60 and C70. We can supply C60 
/99.8%/ 10gram and C70 /99/ 1gram just now and the same amount per each next
month /together with the results of chromatography and mass spectrometric
analysis/ and of course their mixture. The following I know about prices:
talking in USA during my visit/August 92/ C60- more than 1000$ per 1 gram.,
C70- twice more expensive; talking in Moscow-about twice more high prices;
Journal of Inorganic Chemistry,v.31, N 14, 1992. Advertisement of Aldrich Chem.
Comp. C60-156$ per 25 mg; C70, coming soon, 200$ per 10 mg.

I have to look for direct contact with people of fullerene corporation or
others who needs fullerenes. Can you help me? The situation is rather
complicated. If there is no market we have to stop production if there is we
can increase. So we need quick answer. Our price can be cheaper the current
prices in USA but not less than 600$ per gram of C60.

With Best wishes Sincerely Yours Lev
*STUFF DELETED*

>>END OF INCLUDED MESSAGE
From: xenon@drycas.club.cc.cmu.edu
Newsgroups: sci.chem
Subject: Re: Methylene Dichloride
Date: 18 Nov 92 19:16:22 -0500
Distribution: sci.chem
Organization: Carnegie Mellon Computer Club

In article <NORTON.92Nov18172403@joker.optics.rochester.edu>, norton@joker.optics.rochester.edu (Scott Norton) writes:
> 
>        Question:  Does anyone know if there is a "popular" name for
> methylene dichloride??  CH2Cl2  ??
>    I was told it was very common and could probably be obtained at a
> hardware store... so is it a paint thinner or something like that??
> 
> Thanx!
> Scott
> .

I have never heard it called anything other than dichloromethane or methylene
chloride.  The 'di-' is somewhat redundant.

Newsgroups: sci.chem