Exam 2 Test Topics

1
Exam 2 Test Topics

• Closed Book
• 55 minutes (no more)
• Bring pencil, but no calculator
• Lectures 11-20
• Chapter 17 2-6 18 1-4
• Q A Sessions
• Tonight Night, 530 pm - ?, Seaver N Auditorium
• Tuesday, 12 noon -130, Frank Blue Room (?)
• I will be around today and tomorrow except for
• Monday 12-1 4-530
• Tuesday 11-12 after 5 pm

2
Periodic properties

• IE (1st, 2nd, ) , EA Atomic Ionic radii EN
• Period and group explanations of general trends
• Explanation of exceptions
• (happy atoms with filled shells will cost you
  many points)
• Oxidation states
• Acid Strength

3
(No Transcript)
4
Covalent vs. Ionic Bonds

• Diagram potential energy, kinetic energy
• Electronegativity prediction of ionic extent
• Basics of ionic and covalent bonding
• ionic character from dipole moments
• Bond properties length, enthalpy

The lattice energy lowers the energy of a mole
of ionic solid compound compared to a mole of the
diatomic molecules of the same solid because in
the solid there is a) an increased number of
Coulombic interactions b) a difference in bond
length c) a greater attraction between the ionic
pairs d) surface tension A gas-phase ionic
molecule bonds because a) combination of IE and
EA in forming the ions is exothermic b) the
lattice energy is exothermic c) the sharing of
electrons in a bond d) the Coulombic
attraction of the cation and the anion
5
Molecular Orbital Theory for Diatomics

• MO-LCAOs - ? ? bonding and antibonding
  orbitals
• Correlation MO energy diagrams
• Auf Bau, Pauli, Hund ? bond order magnetism
• bond distance and bond energy predictions
• homo vs. hetero, m.o. electron configuration
• relative contribution of atomic orbitals in
  molecular orbitals
• dipole moment explanation

6
N2 F2 B2
7
Polyatomic bonding theory

• Extension to polyatomics
• localized bonds hybridization followed by V.B.
  orbital formation
• prediction of hybridization and structure (bond
  angles)
• multiple bond formation - ? ?
• Polyatomic orbitals written a sums of hybridized
  orbitals and p orbitals
• (Be able to draw a Lewis dot structure, determine
  hybridization of central atoms, and draw
  structure of molecules showing bond angles.)

8
(No Transcript)
9
Delocalized ? molecular orbitals

• Combination of localized (VB) picture for ? bonds
  MO picture for ? bonds
• Resonance structures and delocalized orbitals
• Conjugated double bonds and delocalized orbitals
• Draw picture of orbitals showing extension over 3
  or more centers
• Lowering of ? orbital energy caused by
  delocalization
• Fractional bond orders

10
Circle correct answers. The p ? p transition
for the acetate ion would be at ( lower
higher the same ) energy than the acid
because delocalization ( lowers raises
doesnt change ) the energy of the p orbitals.
Why carrots are orange
11
Spectroscopy

• Molecular energies, relative energies
• Types of transitions and info obtained
• Change in bond properties (distance, energy) due
  to electronic transitions btwn orbitals

Study Hard and Good Luck
12
(No Transcript)