Re: White House Delays Release of Study Showing Toxic Rocket Fuel In Most Americans


"Aidan Karley" <doIlookDAFTenoughTOpost@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
wrote in message
news:VA.00000cff.7e045f01@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
In article <pbkPf.806465$x96.151047@attbi_s72>, George wrote:
That is true. By the way, PERC and PCE are the same substance. 1,1,2,2
tetra-chloro ethylene and perchloroethane are also the same thing. Also
known as Hexachloroethane and Carbon hexachloride.

Two of the synonyms you suggest indicate a six-chlorine molecule ;
one of the synonyms indicates a four-chlorine molecule, and two are
completely agnostic as to the chlorine count.

Cl Cl Cl H Cl H
\ / | | | |
C==C Cl-C--C-Cl Cl-C--C-H
/ \ | | | |
Cl Cl H Cl Cl H

tetrachloro- 1,1,2,2 tetra- 1,1,1 trichloro-
ethylene chloroethane ethane

<SIGH> IUPAC organic nomenclature rules are tedious, awkward,
long-winded, unintuitive and necessary.
I can't be bothered with the 6-chlorine compounds. Drawing the
structures is just too long-winded.

--
Aidan Karley FGS
Aberdeen, Scotland,
Location: 57°10'11" N, 02°08'43" W (sub-tropical Aberdeen), 0.021233

I wondered about the synonyms "Hexachloroethane and Carbon hexachloride",
but those was listed under a site that listed them as synonymous with PCE.
I'm not a chemist (though I play one on TV).

Here is how it is listed by NIOSH - National Institute for Occupational
Health and Safety (which is the information that is used in the hazardous
waste and other industries, in environmental consulting and emergency
management, and others here in the states)"

http://www.cdc.gov/niosh/npg/npgd0599.html

So if I had to choose, I'd say that the first diagram you drew is the
correct one as far as the chemical structure is concerned.

That's a good site for quickly looking up chemicals, by the way. Here is
the index page, if you are interested in looking up some other ones. I
have a pocket edition of this that I use in the field.

http://www.cdc.gov/niosh/npg/npgsyn-a.html

George


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