51A Practice Problems 2
Fall, 2014
1. For each of the following compounds, assign the hybridization states (sp, sp2, sp3) for the
indicated atom.
CH3
CH3CHOCH3
BF3
CH3
CH3
H
H
C C
C=N-CH3
C
H3C
CH3
2. Indicate by arrow the longest C-C bond, the shortest C-C bond, and the shortest C-H bond.
H
H
H
H
C
C
C
H
H
H
C
C
C H
Actual previous test questions:
3. Using the three nitrogen containing compounds below, fill in the missing blanks to make the
statements that follow correct:
NH3
NH2
NH4
The bond angles in H3O+ are similar to the bonds angles in _________.
The bond angles in H3O+ are less than the bond angles in ________ and greater than the
bond angles in _________.
4. For each of the indicated bonds below, label the type of bond and the atomic orbitals that
overlap to make that bond (for multiple bonds label both bonds).
H
H
O
N
O
H
C
H
O
O
C
H
H
H
C
H
C
C
H
Previous test questions (continued)
5.
(12 points) Both boron trifluoride (BF3) and nitrogen trifluoride (NF3) contain a central atom
bonded to three fluorines.
a. Draw the 3-D (line-wedge) structure of each in the boxes provided, showing the correct
geometry. Name the geometry, hybridization, and approximate bond angles for each.
NF3
BF3
geometry:
geometry:
hybridization:
hybridization:
approx. bond angles:
approx. bond angles:
b. One of these molecules has a net dipole moment and one does not. Which is which? Give
a brief explanation of your reasoning.