Lecture 8 Notes: Collision Theory
Collision Theory was invented by Maxwell (1831 - 1879) and Boltzmann (1844
- 1906) in the mid to late 19th century. Viciously attacked until ~1900-1910, when
Einstein and others showed (1910) that it explained many new ex
Lecture 2 Notes: Diatomic Molecules
2
Dissociation of a Diatomic Molecule
AB A + B
*
*
Kp (q A / N)(q B / N) eD00RT[unitless]
*
Kp
(q AB / N)
q
Ng g q
N q
trans,B
3/2
11
0,B 0,A
g
rot,B rot,A
rot,AB
g
3/2
5/2
pAB p
q*
0
vib,A D0 RT
vib,B
q
(2mA ) (kT)
3
Lecture 9 Notes: Dilute Hard Gases
The mean free path. The mean free path is the average distance a particle traverses
before it experiences a collision. In Lecture #31 we determined the average collision
frequency for a particle, Z. The mean time between
Lecture 6 Notes: Large Density Points
We know how to think about the electronic structure of a molecule we know the
orbitals, their energies, their occupancies but with a metal, which we treat as one giant
molecule of N atoms, how do we handle the large n
Lecture 7 Notes: Electron Theory
In the free electron theory we ignored all effects of the nuclei in the
lattice, utilizing a particle-in-the-box approach sans a potential. In the band theory
of solids considered here, we include a very simple potential r
Lecture 10 Notes: Net Mass Flux
We begin by considering the important case of diffusion. Diffusion is a very
important transport property for chemists because it describes the mass transport
necessary to bring molecules into sufficiently close proximity f
Lecture 5 Notes: Lattice Positions
An atomic description of the vibrations of a solid. This will be a more
realisticdescription than Einsteins or Debyes, which are continuum models. Debyes
model
3
works well at low T (T law) and high T, but not so well at
Lecture 1 Notes: Temperature Dependence
TEMPERATURE DEPENDENCE OF Erot AND CV
rot
Low T limit of Erot:
lim Erot lim 6Nkre
T0
T0
rot
lim
lim CV
T0
12Nkr
T
T0
2
2 r
2
e
T
0
2r T
0
1.0
rot
C
V
nR
1.0
Low T Limit
CVrot 12r2 e
E
rot
nR
Note maximum in
2 T
r
Lecture 3 Notes: Repulsive Force
Intermolecular potentials are interactions between molecules up to this point, particles
are treated as independent, ideal particles that do not interact.
Approximation okay for gas molecules at low pressure
All atoms and
Lecture 4 Notes: Simplifications
Goal: For U( q ) 0, calculate Z to obtain corrections for non-ideal contributions to the
equation of state.
Z
~
dq
where
U(q)/kT
3N
e
~
U( q ) = Total Interaction Potential Energy
Simplifications based on form of U( q ):
1