Zeolites
zeo to boil and lithos stone
In 1756, Axel Cronstedt noted that certain compounds lost water upon heating
(Upon exposure to a blow torch, the material hissed and bubbled as if it were boiling)
Zeolites are a class of crystalline aluminosilicates
Crystal Field Stabilization Energy
(CFSE)
The lower energy orbitals are more stable than
the higher energy orbitals.
electrons in t2g orbitals impart extra stability.
The net change in orbital energies after splitting is ZERO.
6 e- in t2g orbitals + 4 e-
Introduction to Solid State Chemistry
The tools are very different from the synthesis of discrete molecules.
involves the modification of the entire solid-state structure.
1.
Sample Preparation -
2.
Annealing -
3.
Characterization -
How do solid state rea
Metallic Bonding
Electron Sea Model
This model describes:
Metals are Excellent Conductors of Electricity
2.
Ductile and Malleability
3.
Shiny
Metals are usually excellent conductors of Heat
size increases
Molecular Orbital Theory
(Band Theory)
conduction
Introduction to Schoenflies Symmetry
1853-1928
Point group notation that is completely adequate to
describe the symmetry of a molecule. This is sufficient
for spectroscopy.
Basic Definitions:
Symmetry Element:
a point, line or plane about which a symmetry
Introduction to Schoenflies Symmetry
1853-1928
Point group notation that is completely adequate to
describe the symmetry of a molecule. This is sufficient
for spectroscopy.
Basic Definitions:
Symmetry Element:
Symmetry Operation:
Proper Rotation:
Improper
Ionic Bonding
(Chapter 5)
Important Concepts!
Oxidation:
Reduction:
Electroneutrality:
Ionic Compounds
Compounds made of ions.
When the EN difference between two elements is >2.0.
The electronegativity difference (EN) is sufficient to remove an electron f
Covalent Bonding
Forces of attraction:
Forces of repulsion:
Molecular Orbital Theory
Atomic Orbitals:
Molecular Orbitals:
Importance of MO Theory
Previous Bonding Theories:
Based upon valence electrons being localized on atoms.
Excellent predictive powers
Inorganic Thermodynamics
(Chapters 6)
Lattice Energy (U)
The energy change for the formation of 1 mole of ionic solid from its
constituent gaseous ions.
The minimum potential energy of the crystalline lattice which minimizes electron-electron
repulsions w
Chem 214 Activity VII
Synthesis of Ferrofluids.
Ferrofluids were developed by Dr. Stephen Pappell in the 1960's to synthesize fluids that
could be controlled in micro-gravity. NASA needed these materials to serve as
lubrication on moving parts in satellit
CHEM 214
(1) -
Calculate the Born Exponent for the following compounds:
i)
(2) -
Worksheet #8
KBr
ii)
SnCl4
III)
SnCl2
Estimate the lattice energy of MgF2 using the Borne - Lande equation. The compound
crystallizes in the CaF2 lattice with Mg-F distances
CHEM 214 Homework III
(1) -
The compound consisting of elements A and B crystallized so that element A
crystallized at the corners and body center of a cubic unit cell and element B crystallized
on the faces of the cubic unit cell. What is the empirical f
1
THE ENERGY LEVELS OF A RIGID ROTOR ARE
EJ
2
J J 1
2I
fixed distance = ro
free rotation: V (r ro ) =
V = ro ) 0
(r =
T =
I 2
L2
=
2
2I
2
I = ro
2
H RR T V
2
2
2
2
x 2
2
y 2
2
z 2
(1)
(2)
Spherical coordinate system
Physics convention
0r
0
0 2
dxdydz
CLASSICAL PICTURE OF
1-D HARMONIC OSCILLATOR
Nearly any system near equilibrium (e.g., a diatomic molecule, electric field,
magnetic field) can be approximated as a harmonic oscillator.
Fx kx m
If we initially stretch to xo
and let go, then the
position
The Schrdinger Equation
(Silbey 9.6)
In 1926, Schrdinger and Heisenberg independently formulated different
versions of Quantum Mechanics.
Schrdinger equation is a postulate and that it is plausible (see Silbey 9.3)
but we do not worry about proving its co
Gibbs Energy
dG T ,P
dG T ,P
0 spontaneous
0 equilibrium
A change can occur spontaneously at constant T and P if the Gibbs (free)
energy decreases.
At constant T and P, the Gibbs1 energy provides a convenient
thermodynamic property for the application
Chemical potential, Fugacity, and Activity
Chemical Potential
U
ni S,V ,cfw_n j i
i
H
ni S,P ,cfw_n j i
i
A
ni T ,V ,cfw_n
i
j i
G
ni T ,P ,cfw_n j i
i
The last definition is most often used, thus, at constant T and P the chemical poten
Chemical Kinetics
Objectives in studying the kinetics of a chemical reaction:
determine the rate law (rate equation) by experiments
Rate = k[ A]x [B]y
the rate law cannot be determined from a balanced equation
elucidate the detailed mechanism by which the
Chemical Equilibrium
Derivation of the General Equilibrium Expression
A B
(0 = A + B)
0=
i Di
i
dG = + VdP + A dnA +B dnB
SdT
dG = + VdP + i dni
SdT
At specified T and P:
dG =A + B dnB = + B d
A dn
A d
G
= A + B
T , P
r G = A + B =i i
i
Reaction G
ENTROPY OF MIXING IDEAL GASES
U 0 q w (ideal gas at constant T)
qrev wrev
S
SB
V
qrev
R ln f
T
Vi
pdV
Vf
Vi
Vi Vf
V
RT
dV RT ln f
V
Vi
change
V
SA nA R ln
VA V change
VA
V
nB R ln
VB V change
VB
V
VA
SA nA R ln
nA R ln
nYA R ln
The Second Law, the Third Law, and the Entropy
The first law showed equivalence of work and heat:
U = q + w , dU = 0 for cyclic process: q = w , so
a cycling engine can convert heat to work.
The Second Law
restrictions on the efficiency of q to w conversi
Using thermodynamic cycles
Can estimate H under one condition using H under a different condition
For example: HT 1 ? , HT 2 is known
Estimate the amount of heat lost when liquid water evaporates at human skin
temperature (35 oC).
step (1)
H2 0 , 35 oC ,
Heat capacities
C
dq
dT
Cv
dqV
dT
CP
dqP
dT
Change in state at constant volume (V = 0)
U
U
=
dU(V , T )
dT + V dV
T V
T
dU = q + w (the first law)
0 for a
dw = pext dV ( pext dV = system with PV-work only)
dUV = dqv
(for a system with PV-work on
Work, Heat, and the First Law
Thermodynamics (G, heat and power) was developed before the
emergence of quantum mechanics; thermodynamics is applicable to any
macroscopic system, even as our understanding of molecular behavior
changes.
In the 17th C, witho
The Maxwell Distribution of Molecular Speeds
For a continuous probability distribution function F(x) of observed value x, the
average value <x> is computed by
< x >=
x F ( x ) dx
(M1)
where F ( x )dx is called a probability density and represents the pro
CHEM 341
PROBLEM SET FIRST LAW
NAME _
Enthalpy change for Al2O3
o
o
From the following data determine the value of H 298.15 H 0 for Al2O3(s).
o
T
K
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
273.16
2
Kinetic Molecular Theory of Gases
The kinetic molecular theory was developed by many different people over 100
years; it was published by R. Clausius1 in 1857. The postulates of the kinetic
molecular theory lead to the ideal gas law.
1) The gas is compose
The SI System of Units
Physical quantity
Mass
Length
Time
Temperature
Amount of substance
Electric current
Luminous intensity
The SI BASE unit
kilogram
meter
second
Kelvin
mole
Ampere
candela
symbol
kg
M
S
K
mol
A
cd
DERIVED Units
1 N (Newton)
1 kg m s-2
Gibbs energy and phase change
At constant T and P, a single-component, two phase
system that describes transfer from to phase
dG
dn dn
= chemical potential at constant T & P
For a spontaneous transfer, G <0
The transfer is spontaneous toward the lowe