Chemistry 405
Test II
Questions (5 point)
1.
Draw the resonance structures and calculate the formal charge for all the atoms in SO3.
2.
Draw the Lewis structures for: CS2; ClF3.
3.
What are the VSEPR shapes for the molecule listed in question 2?
4.
Using your knowledge of Van der Waal forces, list the following in order of increasing
boiling point:
H2O
Xe
SiCl4
LiI
H2
5.
Using Bent=s rules identify and justify the correct structure for PCl2F3.
6.
Complete and balance the following equation, identifying the acid and the base:
SO3 + K2O ---->
7.
Give a possible explanation for the following trend in acid strength:
BF3 < BCl3 < BBr3
8.
What are the suggested hybridizations for the following molecular structures:
Square Planar
Square Pyramid
Trigonal Bipyramidal
9.
What is electronegativity? Describe one method of estimating electronegativity.
10.
What is the Van der Waals Radii? What is its most common use?
Questions (10 point)
1.
Draw and completely label the Molecular Orbital diagram for HF.
2.
Do the Hhckel Calculation for the ethylene (C2H4). Calculate both the energy for the pi
orbitals and the “shape” of the pi M.O’s.
3.
Justify the following trend in bond angles:
PF3
PCl3
PBr3
PI3
97.7o
100.3o
101.0o
102o
4.
List and describe each of the Van der Waal=s forces.
5.
Define and write a chemical equation illustrating the following Acid/Base Definitions:
Lux - Flood
Lewis
Bronsted - Lowry