Last modified: Wed 12/31/1969 06:00:00 pm ACA

It is OK to use your textbook or lecture notes from class, but if you can answers the questions without it that is OK too.

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Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

First Name:

Last Name:

Laboratory Section:

1. Draw the Lewis structure for each of the following compounds, then complete the table; (NOTE: You may wish to consult your textbook to determine the molecular geometry and the terminal atom-central atom-terminal atom bond angle. Additionally you may want to look at the Models360 website we used in class.)


# of valence electrons (molecule/ion)

# of bonding domains on CA(s)

# of nonbonding domains on CA(s)

Molecular Geometry

TA-CA-TA bond angle



2a. What is the bond order (how many bonds) of the S-O bond in SO2? (Note: a single bond has a bond order of 1, a double bond has a bond order of 2, and a triple bond has a bond order of 3.)

b. How many Lewis structures are needed to represent the bonding in SO2?

3a. What is the formal charge (page 383) on the sulfur atom in SO2 in your structure?

b. If the formal charge on the sulfur atom is not 0 in your Lewis Structure in your answer to Question 3a, how can you reduce the formal charge on the sulfur atom to get it to zero?

Answer the following questions using bond energies or Table 9.2 on page 353 in your textbook:

4. How much energy (kJ mol-1) is required to break,

CO bond in CO2?

FF bond in F2?

CF bond in CF4?

OF bond in OF2?

5. Calculate H˚ (kJ mol-1) for the reaction,

CO2(g) + 3F2(g) -----> CF4(g) + OF2(g)

kJ mol-1 (NOTE: The answer I am looking for is between –200 kJ mol-1 and -300 kJ mol-1)

6. Write the formation equation for PCl3(g).


7. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

8. If there is one question you would like to have answered in lecture, what would that question be?