3.07 chemistry
Copy the following questions into your assessment document. You may copy and paste the table, or create a similar table in the document.)
After completing the molecular models, fill in the table below: (18 points)
Molecule
What is the central atom of this molecule?
Number of lone pairs on the central atom
Number of atoms bonded to the central atom
Molecular geometry
Bond angle (based on VSEPR theory)
CCl2F2
C Zero
4
Tetrahedral
109 degrees
HCN
C Zero 2 Linear 180 degrees
H2O
O Two 2 Linear Bent 109 degrees
NH3
N One 3 Trigonal Planar 109 degrees
H2S
S 2
Linear Bent
90 degrees
SO2
S One 2 Linear Bent 120 degrees
PCl4+
P Zero 4 Tetrahedral 109 degrees
NO3-
N Zero 3 Trigonal Planar 120 degrees
O3
O
One
2
Linear Bent 120 degrees
Based on their molecular geometries, which of the molecules (not including the polyatomic ions) are polar? (3 points) NH3, HCN, H2O, SO2 are all polar.
Which of the molecules would experience hydrogen-bonding forces of attraction? (2 points) H2O, NH3, and HCN all experience hydrogen-bonding forces of attraction.
Which of the molecules do you think would have the highest boiling point and which would have the lowest? Explain your answers in terms of molecular geometry and intermolecular forces. (4 points) The highest boiling point is H2O while the lowest boiling point would be SO2.
Compare H2O and H2S in terms of shape, intermolecular forces, and boiling point. Explain your comparison in complete sentences. (4 points)
Based on what you have learned about intermolecular forces, explain why the stream of water “bent” in the introductory activity in this lesson. (4 points) Because water is a polar molecule that has charged ends. When something is held close to the stream of water, it ends up bending.
After completing the molecular models, fill in the table below: (18 points)
Molecule
What is the central atom of this molecule?
Number of lone pairs on the central atom
Number of atoms bonded to the central atom
Molecular geometry
Bond angle (based on VSEPR theory)
CCl2F2
C Zero
4
Tetrahedral
109 degrees
HCN
C Zero 2 Linear 180 degrees
H2O
O Two 2 Linear Bent 109 degrees
NH3
N One 3 Trigonal Planar 109 degrees
H2S
S 2
Linear Bent
90 degrees
SO2
S One 2 Linear Bent 120 degrees
PCl4+
P Zero 4 Tetrahedral 109 degrees
NO3-
N Zero 3 Trigonal Planar 120 degrees
O3
O
One
2
Linear Bent 120 degrees
Based on their molecular geometries, which of the molecules (not including the polyatomic ions) are polar? (3 points) NH3, HCN, H2O, SO2 are all polar.
Which of the molecules would experience hydrogen-bonding forces of attraction? (2 points) H2O, NH3, and HCN all experience hydrogen-bonding forces of attraction.
Which of the molecules do you think would have the highest boiling point and which would have the lowest? Explain your answers in terms of molecular geometry and intermolecular forces. (4 points) The highest boiling point is H2O while the lowest boiling point would be SO2.
Compare H2O and H2S in terms of shape, intermolecular forces, and boiling point. Explain your comparison in complete sentences. (4 points)
Based on what you have learned about intermolecular forces, explain why the stream of water “bent” in the introductory activity in this lesson. (4 points) Because water is a polar molecule that has charged ends. When something is held close to the stream of water, it ends up bending.