From: firstname.lastname@example.org (Robert Parson)
Subject: Re: Intro Phys-Chem Texts
Date: 23 Dec 1997 01:13:55 GMT
In article <349D177F.4FBB@ultranet.com>, crs <email@example.com> wrote:
>Are you using T, S & W because you want a biological orientation? It's
>not that bad a book. Otherwise, there are plenty of fine p-chem books
>around. Alberty, for example, retains much of the clarity of
>presentation that was in older editions (with Daniels) - sort of reads
>like a novel.
That's R. A. Alberty and R. J. Silbey; 2nd Edition Wiley 1997.
> Atkins is extremely clear as well and has superb graphics
>and color coding that directs ones attention to the main points.
Atkins (now in its 5th edition) seems to have the most staying power.
We keep coming back to it after trying out other books.
>While I'm here, let me toss off a question. What, in your opinion, are
>the three most important "take-home" messages that a student can get
>from a p-chem course (other than some pithy comment about p-chemists not
>getting jobs and so on). I have my own ideas but I'd like to hear
Here are three profound discoveries of physical chemistry - so basic
that we often forget just how long it took to arrive at them.
1. Chemical forces are electrical in origin. It is not necessary to
introduce some new kind of fundamental force in order to understand
2. The concept of a thermodynamic cycle - you can calculate the energy
release in a chemical reaction, or the equilibrium constant for a
chemical reaction, by combining data about other reactions with
physical properties of compounds. Suppose you want to know the first
two CH bond energies in ethylene. Proceed as follows:
a.) Use photoelectron spectroscopy to measure the electron affinities
of CH2=CH and CH2=C.
b.) Use a flowing afterglow/selected-ion-flow-tube reactor to measure
the gas phase acidities of CH2=CH2 and CH2=CH.
c.) Combine a.) and b.) with the ionization potential of H.
[See K. M. Ervin et al., JACS _112_, 5750, 1990.]
3. Chemical reactions are governed by the statistics of infrequent
events. For a reaction with a reasonable activation energy, the
rate is determined not by the average molecules but by a very few very
fast molecules. The average speed depends only weakly on temperature,
a sluggish square root, but the fraction of fast guys goes up
exponentially. Small changes in means translate into whopping changes
in the tails of the distribution - the difference between the average
heights of US males and females is only 4 inches, but how often do
you run into Sigourney Weaver on the street?