Name:
Date:
AP Chemistry
U4Q1: Molecular Geometry
Multiple-Choice
MC: ________
FR: _________
Raw: ________
Curve: _______
1. [3] Lewis electron-dot diagrams for CO2 and SO2 are given above. The
molecular geometry and polarity of the two substances are
a. The same because the molecular formulas are similar
b. The same because C and S have similar electronegativity values
c. Different because the lone pair of electrons on the S atom only affects the
polarity by making S the negative end of a dipole
d. Different because S has a greater number of electron groups (regions of electron
density) surrounding it than C has
2. [1] Nitrogen triiodide, NI3, is an unstable molecule that is used as a contact explosive. Its
molecular geometry is…
a. Tetrahedral
b. Trigonal Pyramidal
c. Square planar
d. Octahedral
3. [2] Which of the following compounds would have the smallest bond angle around the
central atom?
a. NH3
b. CH4
c. PH3
d. NH2-
1
Name:
Date:
AP Chemistry
4. [3] Both ammonia (NH3) and methane (CH4) have nearly equivalent bond angles,
however only one of these molecules is considered polar. Which statement accurately
describes which molecule is polar with the correct reason?
a. CH4 polar because it is tetrahedral so all bond angles are equivalent indicating a
polar molecule
b. NH3 is polar because there is a net dipole moment pointing in the direction of the
lone pair
c. NH3 is polar because Nitrogen is more electronegative than Carbon
d. NH3 is polar because it has a tetrahedral geometry
5. [2] The hybridization of the oxygen atom labeled ‘y’ in the structure below is
__________ and bond angle around this atom is __________.
a.
b.
c.
d.
sp, 180°
sp2, 109.5°
sp3, 105°
sp3, 109.5°
6. [1] Hydrogen Cyanide (HCN) is an extremely poisonous liquid that boils just slightly
above room temperature (79 ˚F). How many total sigma bonds would you expect to
form in this compound?
a. 1
b. 2
c. 3
d. 4
7. [2] Which of the following molecules would have the shortest bond?
a. I2
b. CO
c. CCl4
d. O2
2
Name:
Date:
AP Chemistry
8. [2] Based on the Lewis structures drawn for NO3- below, which of the following
structures would be the most likely to exist?
a.
b.
c.
d.
Structure 1
Structure 2
Structure 3
Both Structures 2 and 3 would equivalent
9. [3] The BF3 molecule is nonpolar, whereas the NF3 molecule is polar. Which of the
following statements accounts for the difference in polarity of the two molecules?
a. In NF3, each F is joined to N with multiple bonds, whereas in BF3, each F is joined
to B with single bonds
b. N-F bonds are polar whereas B-F bonds are nonpolar
c. NF3 is an ionic compound, whereas BF3 is a molecular compound
d. Unlike BF3, NF3 has a nonplanar geometry due to an unshared pair of electrons
on the N atom
10. [1] What would the bond order be for N2?
a. 1
b. 2
c. 3
d. 4
3
Name:
Date:
AP Chemistry
THIS PAGE INTENTIONALLY LEFT BLANK
4
Name:
Date:
AP Chemistry
Free Response
1. Methanamide, CH3NO, is a liquid at 25 ˚C. The complete Lewis structure for
methanamide is shown below:
a. In the molecule, angle x is not 180˚. Estimate the observed angle. Justify your
answer.
b. In the molecule, angle y is not 90˚. Estimate the observed angle and explain your
answer in terms of electron domains.
c. Which bond would you expect to be more polar, the C-H bond or the N-H bond?
Explain.
d. What would you expect the hybridization to be around each central atom in
methanamide? Explain your answer.
e. Consider a molecule with the formula CH2O2. The structure of this molecule has
a geometry around the carbon atom similar to the geometry around carbon in
methanamide. In the box below, draw the complete Lewis structure for the
molecule.
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
5
Name:
Date:
AP Chemistry
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
6