Exam 1 review

Chapter 8 Formal Charge only (in sec 8.5)

How do we calculate formal charges on atoms in Lewis structures?
How do we use formal charges to help decide which of several possible Lewis structures is the most stable?

Chapter 9

What is the main idea behind the VSEPR Model?
What are the five electron-domain geometries? Know Table 9.1.
What is the difference between electron-domian geometry and molecular geometry?
What is the effect of lone (nonbonding) electron domains on molecular geometry?
When deducing a molecular geometry, how do we deal with multiple bonds?
Be able to deduce electron-domain and molecular geometry for molecules of type AB_n with 2, 3, 4, 5, and 6 electron pairs about the central atom (e.g., problem 9.12)
Know the shapes in Tables 9.2 and 9.3
How do we deduce the bond angles in molecules with no single central atom?
When is a polyatomic molecule said to be polar?
How is the degree of polarity of a molecule measured?
What geometries for polyatomic molecules lead to nonpolar molecules?
What are the fundamental ideas of valence-bond theory?
Can s orbitals overlap with p orbitals?
Can p orbitals which are not directed along the internuclear axis overlap?
What, in terms of orbital overlap, is the difference between a sigma (s) and a pi (p) bond?
Why do we modify valence-bond theory to give hybrid orbitals?
How does hybrid orbital theory explain VSEPR geometries?
How do we determine the hybrid orbital set used by the central atom in a binary compound?
How many atomic p-orbitals are left over for pi bonding in the sp, sp², and sp³ hybrid orbital sets?
How does hybrid orbital theory explain multiple bonding?
What is meant by delocalized bonding? How do we determine whether delocalized bonding
If two atomic orbitals (AOs) are combined, how many molecular orbitals (MOs) must form? How many MOs result from combination of 6 AOs?
What types of AOs can combine to give a sigma-type MO? A pi-type MO?
Know the orbital ordering of MOs for homonuclear diatomic molecules B₂ - F₂ - recall that the MO order switches at O₂, and understand why this is.
How do we calculate bond order from an MO diagram?
What do bond orders of 1, 2, and 3 mean?
How do we tell if a molecule is paramagnetic or diamagnetic from it's MO diagram?

Ch 9 suggested problems: 9.1, 9.3, 9.5, 9.7, 9.9, 9.11, 9.15, 9.17, 9.23, 9.25, 9.31, 9.37, 9.47, 9.57, 9.58.

Chapter 11 (11.1-11.6)

What is the difference between inter- and intramolecular forces? Which is typically stronger?
What are some characteristic properties of the three states of matter?
How does the strength of intermolecular forces compare to the kinetic energy in a solid? In a liquid? In a gas?
Under what circumstances does an ion-dipole force exist? A dipole-dipole force?
What is the nature of the London dispersion force? From what does it arise?
How does the dispersion force change with molecular weight?
Be able to compare attractive forces for molecules of similar size and shape.
Be able to compare attractive forces for molecules of similar polarity and shape.
Under what circumstances does hydrogen bonding occur? Why are hydrogen bonding interactions so strong?
Why does ice float?
Why is the energy needed to boil the liquid phase of a substance typically larger than the energy needed to melt the solid phase?
Which phase changes are endothermic? Which are exothermic?
What is the definition of vapor pressure? How is vapor pressure related to intermolecular forces?
What is meant by the term dynamic equilibrium?
What happens when a liquid boils?
What is meant by the normal boiling point of a liquid? The normal melting point?
Why would it take longer to cook mac and cheese atop Mt. Ashland than at Brookings?
What is a phase diagram? What variables are plotted along the x and y axes?
What is the triple point? The critical point?
What information can we get about intermolecular forces can we get from the critical temperature?
Be able to interpret a phase diagram by varying T at constant P and vice versa.
What is unique about the solid-liquid line in the water phase diagram?
Practice problems: 11.1, 5, 7, 11, 13, 17, 29, 39, 43, 49

Remember - 5 extra credit points will be given for a note card turned in before the exam!

Send questions, comments, etc to chapman@sou.edu

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doug chapman chapman@sou.edu 1/30/08