Inorganic Chemistry

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Inorganic Chemistry

• Duward Shriver
• and
• Peter Atkins

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CHEM422 Lab

• Wednesday
• Friday
• Other

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Periodic Table Exam

• Write chemical symbol for first 36 elements in
  proper location on blank periodic table
• Worth 40 points total
• Up to 36 for elements 1-36
• No more than 4 points for other elements
• First attempt during week of Feb. 10.
• Part of 400 total points for Homework

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Chapter 1

• Atomic Structure

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Structure of the Atom
protons found in nucleus relative charge of
1 relative mass of 1.0073 amu

• Composed of
• protons
• neutrons
• electrons

neutrons found in nucleus neutral charge relative
mass of 1.0087 amu
electrons found in electron cloud relative charge
of -1 relative mass of 0.00055 amu
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Atomic Number, Mass Number, Isotopes

• Atomic number, Z
• the number of protons in the nucleus
• the number of electrons in a neutral atom
• the integer on the periodic table for each
  element
• Mass Number, A
• integer representing the approximate mass of an
  atom
• equal to the sum of the number of protons and
  neutrons in the nucleus
• Isotopes
• atoms of the same element which differ in the
  number of neutrons in the nucleus
• designated by mass number

Nuclear Notation
A E Z
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Isotopes vs. Allotropes

• Isotopes - atoms of the same element with
  different numbers of neutrons
• - different compounds with the same formula
• Allotropes - different forms of an element
• Carbon exhibits both
• Isotopes C-12 C-13 C-14
• Allotropes graphite, diamond, and fullerenes

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Big-Bang

• starts with universe as a singularity with
  infinite density and temperature, only radiation
  exists
• sudden expansion leads to rapid drop in
  temperature and density
• nuclear particle transformations convert most of
  universes energy to protons and deuterons

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The Origin of the Elements

• Nucleosynthesis of light elements
• Nucleosynthesis of heavy elements

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Hydrogen Burning

• Hydrogen Burning (fusion)
• 4 1H ---gt 4He 2 positrons 2 neutrinos
• 2.5 x 106 MJ/mol
• after about 1/10 of hydrogen consumed, changes to
  helium burning

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Helium Burningand Helium Reactions

• Helium Burning (fusion)
• 3 4He ----gt 12C
• Helium Reactions
• 12C 4He ---gt 16O
• 16O 4He ---gt 20Ne
• 20Ne 4He ---gt 24Mg
• when temperature reaches 5 x 108 K, carbon fusion

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Carbon Burning

• 2 12C ---gt 23Na 1H
• 2 12C ---gt 20Ne 4He
• etc.

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Neutron Capture

• 68Zn 1n ---gt 69Zn ---gt 69Ga b
• 80Br 1n ---gt 81Br ---gt 81Kr b
• etc.

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Average Binding Energy per Nucleon
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Relative Penetrating Powers of Radiation
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Decay Scheme for Uranium Series
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Classification of the Elements

• Metals
• Lustrous, malleable, ductile, electrically
  conducting solids at room temperature
• Nonmetals
• Often gases, liquids, or solids that do not
  conduct electricity appreciably
• Metalloids
• Elements, alloys or compounds that possess some
  of the characteristics of metals and some of
  nonmetals

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Classification of the Elements

• Metallic elements combine with nonmetallic
  elements to give compounds that are typically
  hard, non-volatile solids
• When combined with each other, the nonmetals
  often form volatile molecular compounds
• When metals combine (or simply mix together) they
  produce alloys that have most of the physical
  characteristics of metals

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Development of Periodic Table

• Dmitri Mendeleev - Russian
• 1869 - Periodic Law - allowed him to
  predict properties of unknown elements

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Missing elements 44, 68, 72, 100 amu
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CEN COVER STORYDec. 20, 2004
Organometallic and Inorganic Chemistry
A stable compound containing a silicon-silicon
triple bond.Sekiguchi A, Kinjo R, Ichinohe
M.Department of Chemistry, Graduate School of
Pure and Applied Sciences, University of Tsukuba,
Tsukuba, Ibaraki 305-8571, Japan.
sekiguch_at_staff.chem.tsukuba.ac.jpThe reaction
of 2,2,3,3-tetrabromo-1,1,4,4-tetrakisbis(trimeth
ylsilyl)methyl-1,4-diisopropyltetrasilane with
four equivalents of potassium graphite (KC8) in
tetrahydrofuran produces 1,1,4,4-tetrakisbis(trim
ethylsilyl)methyl-1,4-diisopropyl-2-tetrasilyne,
a stable compound with a silicon-silicon triple
bond, which can be isolated as emerald green
crystals stable up to 100 degrees C in the
absence of air. The SiSi triple-bond length (and
its estimated standard deviation) is 2.0622(9)
angstroms, which shows half the magnitude of the
bond shortening of alkynes compared with that of
alkenes. Unlike alkynes, the substituents at the
SiSi group are not arranged in a linear fashion,
but are trans-bent with a bond angle of 137.44(4)
degrees.
Zinc-Zinc Bond
Decamethyldizincocene, synthesized by Carmona and
coworkers, is the first stable molecule with a
bond between two zinc atoms (green). Hydrogens
are not shown.
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Periodic Table of the Elements
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Quantum MechanicsWave Nature of Electrons
Atomic Force Microscope
Crommie, Lutz Eigler
http//www.almaden.ibm.com/vis/stm/corral.html
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http//mrsec.wisc.edu/
http//mrsec.wisc.edu/
Developed in collaboration with the Institute for
Chemical Education and the Magnetic Microscopy
Center University of Minnesota http//www.physics.
umn.edu/groups/mmc/
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Sample
http//www.nsf.gov/mps/dmr/mrsec.htm
http//www.nsf.gov/mps/dmr/mrsec.htm
Pull Probe Strip
Pull Probe Strip
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Which best represents the poles?
(a)
(b)
(c)
North
South
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Quantum Numbers

• n gt principal quantum number, quantized energy
  levels, which energy level
• n 1, 2, 3, 4, 5, 6, 7, etc.

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Quantum Numbers

• l gt secondary quantum number, quantized orbital
  angular momentum, which sublevel or type of
  orbital
• s type orbital l 0
• p type orbital l 1
• d type orbital l 2
• f type orbital l 3
• g type orbital l 4

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Quantum Numbers

• m gt magnetic quantum number, quantized
  orientation of angular momentum, which orbital
  within sublevel
• s type orbital m 0
• p type orbital m 1, 0 or -1
• one value for each of the three p orbitals
• d type orbital m 2, 1, 0, -1 or -2
• one value for each of the five d orbitals
• f type orbital m 3, 2, 1, 0, -1, -2 or -3
• one value for each of the seven f orbitals

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Hydrogenic Energy Levels

• hcZ2R
• E - -----------
• n2
• where n 1, 2, 3, hhh
• R Rydberg constant
• mce4
• R ----------- 13.6 eV
• 8h3ceo2

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s- and p-orbitals
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d-orbitals
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f-orbitals
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Many Electron Atoms

• Electronic Configuration
• Pauli exclusion principle
• No more than 2 electrons can occupy a single
  orbital
• No two electrons can have the exact same four
  quantum numbers

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Electron Filling Order Diagram
Start here

• 1s
• 2s 2p
• 3s 3p 3d
• 4s 4p 4d 4f
• 5s 5p 5d 5f
• 6s 6p 6d
• 7s 7p

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Ground state electronic configurations
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Electronic Configuration

• As atom
• 33 electons
• 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p3
• or
• Ar 4s2, 3d10, 4p3

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• Mn Ar4s2 3d?
• How many d electrons does Mn have?
• 4, 5, 6

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Electronic Configuration

• negative ions
• add electron(s), 1 electron for each negative
  charge
• S-2 ion
• (16 2) electrons
• 1s2, 2s2, 2p6, 3s2, 3p6

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Electronic Configuration

• positive ions
• remove electron(s), 1 electron for each positive
  charge
• Electrons are first removed from orbital with
  highest n l
• Mg2 ion
• (12-2) electrons
• 1s2, 2s2, 2p6
• Fe atom Fe2 ion
• (26) electrons (26-2) electrons
• Ar4s23d6 Ar4s03d6

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• How many valence electrons are in Cl, Ne3s2
  3p5?
• 2, 5, 7

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Shielding

• Z gt effective nuclear charge
• Z Z - S
• S gt shielding as defined by Slaters Rules
• http//en.wikipedia.org/wiki/Slater's_rules

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Slater's Rules for Calculating Shielding

• for ns, np electrons (e-s), e-s to the right in
  the modified electronic configuration contribute
  nothing
• 2. for ns, np e-s, other electrons of same
  group contribute 0.35 each (except 1s, 0.3)
• 3. each electron in n - 1 group, contribute 0.85
• 4. each electron in n - 2 group, contribute 1.0
• 5. nd nf group, rules 1 2 remain the same,
  all electrons to the left contribute 1.0
• modified electronic configuration
• 1s2s2p3s3p3d4s etc

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Examples for the 4 s electron in Cu atom

• 1s22s22p63s23p63d104s1
• n - 2 group gt 10 1.0
• n - 1 group gt 18 0.85
• n group gt 0 0.35
• Z 29 - ((10 1.0) (18 0.85) (0
  0.35))
• 29 - 10 - 15.3
• 3.7

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Example for a 3 d electron in Cu atom

• 1s22s22p63s23p63d104s1
• rule 5. group
• 18 1.0
• 9 other d electrons 0.35
• Z 29 - ((18 1.0) (9 0.35))
• 29 - 18 - 3.2
• 7.8

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Effective Nuclear Charge
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Atomic Radius

• decrease left to right across a period
• as nuclear charge increases, number of electrons
  increase however, the nucleus acts as a unit
  charge while the electrons act independently,
  pulling electrons towards the nucleus, decreasing
  size
• increase top to bottom down a group
• each additional electron shell shields the
  outer electrons from the nuclear charge
• increases from upper right corner to the lower
  left corner

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Ionic Radius

• same trends as for atomic radius
• positive ions smaller than atom
• negative ions larger than atom
• Isoelectronic Series
• series of negative ions, noble gas atom, and
  positive ions with the same electronic
  confiuration
• size decreases as positive charge of the
  nucleus increases

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Ionization Energy

• energy necessary to remove an electron to form a
  positive ion, I
• low value for metals, electrons easily removed
• high value for non-metals, electrons difficult to
  remove
• increases from lower left corner of periodic
  table to the upper right corner

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Ionization Energies

• first ionization energy
• energy to remove first electron from an atom
• second ionization energy
• energy to remove second electron from a 1 ion
• etc.

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Electron Affinity

• energy released when an electron is added to an
  atom
• same trends as ionization energy, increases from
  lower left corner to the upper right corner
• metals have low Ea
• nonmetals have high Ea

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Electronegativity

• Pauling Scale
• relative attraction of an atom for electrons, its
  own and those of other atoms
• same trends as ionization energy, increases from
  lower left corner to the upper right corner
• fluorine E.N. XP 4.0
• based on the energetics of bond formation

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Electronegativity

• Milliken Scale
• Based on the average of the ionization energy and
  electron affinity
• XM ½(I Ea)

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