1) Which of the following molecules are polar? Explain your choice.
a. COF2
b. SiF4
c. PF3
d. CS2
2) For each of the following compare the electron geometry (based on total electron groups)
and molecular geometry (shape of the molecule) around:
Central atom for: PF5, SeF4, KrF2
3) Arrange the following (Explain your answer – show Lewis structures and geometry
where applicable)
From lowest to highest bond angle
PH3, ClO4-, XeF4, SCl2
4) Describe the bonding for the following molecules using valence bond theory:
a. HBr b. H2O
5) For the underlined atom in the following molecules, predict the electron geometry, the
molecular geometry, and the hybridization of the atom
a. BCl3
b. CO2
c. SO2 (for the central oxygen atom) – try doing this for all resonance structures (the
hybridization of the central atom should be the same for each resonance structure
6)
For the indicated atoms (denoted with an arrow), (i) to
(iii), answer the following questions. Lone pairs are
not indicated in the structure. Consider the structure as
given (no need to consider resonance structures). All
atoms have formal charge of 0. (Use valence bond
theory and hybridization to describe the bonding.)
a) For (i)
1. What is the electron and molecular geometry at N?
2. Circle the one value that best describes the H-N-H bond angle.
>90° to <109.5° 109.5° 120° >120° to <180
b) For (ii)
1. What is the molecular geometry at C (ii).
2. Circle the one value that best describes the O-C-C bond angle.
>90° to <109.5° 109.5° 120° >120° to <180
3. Using principles of hybridization, describe all the orbitals involved in the various sigma
and pi bonds formed by C (ii) with the adjacent carbons.
c) For (iii)
1. What is the electron and molecular geometry at O (iii).
2. Circle the one value that best describes the H-O-C bond angle.
>90° to <109.5° 109.5° >109.5° to <120° 120° >120° to <180
7) Below is the structure of Adenine (this is the building block of nucleic acids), determine
the orbitals (using Valence bond theory + hybridization) involved in bonding between the
highlighted atoms
