THERMO - PART 3
Week 3
9.11 Bond Enthalpy
# Define bond energy.
# Estimate H from bond energies.
Ionic and Covalent Bonding
9.1 Describing Ionic Bonds
# Define ionic bond.
# Explain the Lewis electron-dot symbol of an atom.
# Use Lewis symbols to represen
CHEM 2400/2480
CHEM 2400/2480 Analytical Chemistry I
Course Notes
FALL 2016
Dr Wojciech Gabryelski
Fall 2009
1
CHEM 2400/2480
Table of Contents
What is Analytical Chemistry?
Some Important Terms in Analytical Chemistry:
Parameters Characterizing Analytica
CHEM 2400/2480
Problem Set 2: Statistics, error analysis and standard curves
1.
The following 10 results are from experimental measurements for the atomic weight of
carbon:
12.0112, 12.0210, 12.0102, 12.0118, 12.0111, 12.0106, 12.0113, 12.0101, 12.0097,
1
Problem Set 1: Calculation of concentrations and preparation of solutions
1.
Calculate the analytical concentration and the species concentrations for the following: an
aqueous solution that contains 1.50 g of acetic acid in 25.0 L (the acid is 12.4 %
dis
4.2. Molecular Properties from VB Theory
a) Bonding and Bond distances
The wavefunction that describes a bonding pair of electrons:
b = a(h1) + b(h2)
where h1 and h2 are HAOs on adjacent atoms pointing towards each other.
(Source: Purcell + Kotz, Inorgan
1. Atomic Concepts
Reading for this section: Chapter 1
1.1 Review of Quantum Mechanical Principles
Schrdinger Equation:
H = E
Q. What is a (classical) Hamiltonian?
H is defined to be the sum of T (kinetic energy) and V (potential energy)
H=T+V
THEREFORE,
4. Valence Bond (VB) Theory
Related Textbook Reading: Chapter 2, Sections 2.4 2.6
The first quantum mechanical theory of bonding (Pauling, Heitler, London, etc., 1930s)
Only considers the bonding between two atoms at a time localized bonds.
Essential feat
1.4 Estimating the effective nuclear charge: Slater Type Orbitals (STO)
NOTE: This section does appear in your textbook in only abbreviated form. For further
understanding, consult, e.g., Miessler and Tarr.
PREMISE: We can calculate an approximate value f
Lecture Notes for
CHEM 3640
Chemistry of the Elements I
Main Groups
Developed by
Marcel Schlaf (2000-04; 2008-09)
and Kathryn Preuss (2005-07; 2010; 2015)
Department of Chemistry
University of Guelph
2015
1
Recommended textbook for this course:
Inorganic
1.6. Review of Electronegativity ()
Reading for this section: Chapter 1.7, Chapter 9
CONCEPT:
Electronegativity is a very useful concept for the explanation or
understanding of chemical reactivity throughout the periodic table.
There are many definitions
1.10 The Vector Model of the Atom
Classical Physics:
If you go back to your first year physics textbook, you will find momentum p (= m v) has
an angular counterpart, angular momentum l (= r x p), as shown in the diagram below.
(Recall: Right-hand rule!)
I
2. Molecular Structure and Bonding
Reading: Chapter 2, sections 2.1 - 2.3, 2.13 - 2.16
Review of Lewis dot structures:
Lewis proposed that a covalent bond is formed when two neighboring atoms share an
electron pair. Single bond (A:B) Double bond (A:B) Tri
3. Symmetry and Group Theory
READING: Chapter 6
3.1. Point groups
Each object can be assigned to a point group according to its symmetry elements:
Source: Shriver & Atkins, Inorganic Chemistry, 3rd Edition.
The symmetry elements can be considered operator
3.4. Characters and Character Tables
3.4.1. Deriving character tables
a) The fluffy way
Def.: The character of a matrix is the sum of all its diagonal elements. (Also called the
trace of a matrix).
0
1 0
i = 0 1 0
0 1
0
trace = -3
For a given point gro
Problem Set #3
Fall 2006
SOLUTIONS
5-7 We need to use our fundamental statistics to nd the mean and the standard deviation of this
spread of data. Using Excel, or your calculator, or your abacus, you should nd the following:
Mean = 1.003
Standard Deviatio
Problem Set #9
Fall 2006
SOLUTIONS
17-2. The broad band at 3400 cm-1 is typical of alcohols. The peak at 1650 cm-1 is consistent
with an alkene double bond. No peak above 1700 cm-1 suggests the absence of a ketone or aldehyde. The molecule vinyl alcohol i
Problem Set #6
Fall 2006
SOLUTIONS
14-1 (a) Note that in this question we are not using the calibration curve to nd an unknown.
rather we are only be asked to characterize the calibration curve. The data comes nicely out of
the LINEST function in Excel. T
Problem Set #7
Fall 2006
SOLUTIONS
15-3 Fluorometry usually has detection limits which are several orders of magnitude lower than
spectrophotometry. This larger linear range arises because uorometry has a response which, to
rst approximation, is linear wi
Problem Set #4
Fall 2006
SOLUTIONS
6-14 The denition relating absorbance and transmittance is
A = log10 T
This equation inverted gives
T = 10A
For these three examples, we have
(a) T = 100.375 = 0.422 = 42.2%
(b) T = 101.325 = 0.0743 = 4.73%
(c) T = 100.0
Problem Set #5
Fall 2006
SOLUTIONS
13-1 The denition relating absorbance and transmittance is
A = log10 T
This equation inverted gives
T = 10A
For these three examples, we have
(a) T = 100.0510 = 0.889 = 88.9%
(b) T = 100.918 = 0.121 = 12.1%
(c) T = 100.3
Problem Set #8
Fall 2006
SOLUTIONS
16-3 A vibration is infrared active if the stretching leads to a change in the dipole moment. You
can analyze this by trying to visualize the charge distribution around the molecule. Remember
that the dipole moment is th
Problem Set #2
Fall 2006
SOLUTIONS
3-1 The input voltage is a given as a sine wave (starts at 0 and time 0) and is shown in blue on
each of these graphs. The relative amplitude of the output voltage will depend upon the values
of R and C for parts a, d, a
Problem Set #10
Fall 2006
SOLUTIONS
20-2 The most fragmentation and hence the most complex spectra come from electron impact
ionization. Field ionization will produce the simplest spectra. Chemical ionization and electron
impact ionization are more sensit