Need Freon TF Substitute for Head Cleaning

From: Don Maslin <donm_at_cts.com>
Date: Tue Jul 11 18:23:50 2000

On Tue, 11 Jul 2000, Pete Turnbull wrote:

> On Jul 11, 10:19, CLASSICCMP_at_trailing-edge.com wrote:
>
> > Stupid chemistry question from someone who took too many physics classes
> > and not enough chemistry:
> >
> > What's the difference between trichlorotrifluoroethane and
> > 1,1,2-trichloro-1,2,2,trifluoroethane? Are they different names
> > for the same stuff, or two different stuffs?
>
> Just the positions of the various halogen atoms relative to each other.
> The 1,1,2 form specifies a particular arrangement, the other is
> non-specific.
>
> Schematically, this is 1,1,2-trichloro-1,2,2,trifluoroethane:
>
>
> Cl F
> | |
> F--C---C--Cl
> | |
> Cl F
>
> In other words each carbon atom has one halogen of one type and two of the
> other. There's one other possible arrangement[1]; where all the chlorine
> is on one carbon, and all the fluorine is on another, which would be
> 1,1,1-trichloro-2,2,2-trifluoroethane. I've no idea if that makes any
> significant difference to any of the properties you and I would be
> interested in, but I suspect not, and that most trichlorotrifluoroethane is
> a mixture of the two.
>
> [1] From my 2-D ASCII art, you might think there are other arrangements, eg
> swapping the position of the fluorine for one of the chlorines on the first
> carbon atom. However, if you think 3-D, and imagine the carbon as one apex
> of a triangular pyramid (meeting the second carbon at the apex of another
> pyramid) and also realise that the carbons can rotate relative to each
> other, you'll see that all the other permutations are equivalent.
>
> BTW, this is iso-propyl alcohol:
>
> H
> /
> H O H
> | | |
> H--C---C---C--H
> | | |
> H H H
>
> You could also call it 2-hydroxy-propane, or propan-2-ol. The O-H group is
> what makes it water miscible (in fact, it's mildly hygroscopic), and of
> course it's also highly flammable, unlike the chloroflurocarbons. To get
> ordinary ethyl alcohol, chop off one of the carbons and two corresponding
> hydrogens.

Then add essence of juniper berry and other botanicals, perhaps a swish
of vermouth, and a twist of lemon, shaken not stirred with ice, and...

                                                 - don
 
> --
>
> Pete Peter Turnbull
> Dept. of Computer Science
> University of York
>
Received on Tue Jul 11 2000 - 18:23:50 BST