>> Oxygen is quite polar (and is in the triplet ground state, and therefore
>> a free radical).
>
>O2 is not polar, i.e., there is no charge separation in the O2 molecule (no
>+ end and no - end).
I guess you've never heard of Van der Waals forces. For instance, how do
seemingly two materials without a dipole moment (say, hexane and wax)
solvate each other?
>Further, there is essentially NO free radical oxygen
>in the troposphere (except for some transients induced by photochemistry).
Again, you are mistaken. Oxygen in its ground state is a triplet
radical. Look it up.
http://hep.ucsd.edu/~branson/130/130b/130b_notes_prod/node137.html
>> To suggest that water and air do not interact is
>> inaccurate.
>I never said they don't interact. Just that they don't interact via the
>same chemical forces that occur when a solvent (like water) dissolves
>something. A solvent "latches on" to a molecule of the solute. That is NOT
>happening when water evaporates into the air. If the O2 & N2 were replaced
>with helium or argon, water would still evaporate and there would still be
>humidity.
Last time I checked, there is only one force that applies to molecular
interactions, the electromagnetic force. Weak or strong, this is the
same force for all interactions. Chemists will further divide this based
upon the origin of the force (i.e. ionic, covalent, H-bonding, Van der
Waals) but when you boil it all down, its all the same.
>> If water and air were not miscible, they would form separate
>> layers, just as water and an organic solvent do.
>Actually, if you took a tall column of air and maintained it at the same
>temperature and pressure throughout, the water vapor (which is just a bit
>more than half the molecular weight of N2 & O2) WOULD rise to the top.
No, it would not. You are neglecting a) brownian motion and convection,
b) interactions between air and water. The surface tension for water and
air ranges from 75-53 dynes/cm. This is sufficient to keep things mixed.
>> Don't get caught in the
>> trap of looking at things only one way. Laws of thermodynamics, kinetics
>> and interactions are all intertwined. Nature really doesn't care what
>> the materials are, their interactions and states are all governed by the
>> same principles.
>
>Although thermodynamics and kinetic theory are often taught as part of
>chemistry courses, they are different than chemistry. Chemistry involves
>attractive forces between molecules/elements. Thermodynamics/kinetics is
>more or less the application of Newtonian mechanics to an ensemble of
>objects.
If you think that chemistry and physics are somehow different from each
other, then the folks who edit the Journal of Chemical Physics (not to
mention the Journal of Physical Chemistry) may take issue with you as
well as those who are in interdisciplinary fields of Meteorology and
Astronomy. Chemistry is physics applied to life. The theories and laws
of chemistry are based upon physics and math. While we can't fully
describe anything more complicated than a three body system (hydrogen
molecule ion) approximations can be made using the Schrodinger equation
and various other theories (Huckle and others) to give very good
agreement of mathematical and physical theories to real chemical
interactions and reactions. A large business now exists selling
molecular modeling software to synthetic chemists for designing molecules
on the computer before you step into the lab. It will come as a great
surprise to chemists who use thermodynamics and kinetics to describe
physical reality that somehow they are doing it differently than
physicists.
Mark Ross
markr13_at_comcast.net
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