,Chapter 1—Structure and Bonding
SHORT ANSWER
1. Give the ground-state electron configuration for carbon (atomic number 6).
ANS:
1s22s22px12py1 or 1s22s22p2
2. Give the ground-state electron configuration for fluorine (atomic number 9).
ANS:
1s22s22px2 2py2 2pz1 or 1s22s22p5
3. Give the ground-state electron configuration for magnesium (atomic number 12).
ANS:
1s22s22p63s2
4. How many electrons does silicon have in its valence shell?
ANS:
four
Exhibit 1-1
Write valid Lewis (electron-dot) structures for each formula below. Show all electrons as dots and
show all non-bonding electrons.
5. C2Cl4 tetrachloroethylene
ANS:
6. CO2 carbon dioxide
ANS:
7. CH4O methanol
1
,Structure and Bonding
ANS:
Exhibit 1-2
Consider the structure of urea, shown below, to answer the following question(s).
8. Refer to Exhibit 1-2. Fill in any non-bonding valence electrons that are missing from the
line-bond structure.
ANS:
9. Refer to Exhibit 1-2. The carbon atom in urea is:
a. sp3 hybridized
b. sp2 hybridized
c. sp hybridized
d. not hybridized
ANS:
b
10. Refer to Exhibit 1-2. The predicted NH2−C=O bond angle in urea is:
a. 109.5°
b. 120°
c. 180°
d. not predictable
ANS:
b
2
, Chapter 1
Exhibit 1-3
Determine the hybridization for the indicated atoms in each structure below.
11. Refer to Exhibit 1-3. The hybridization of this oxygen atom (A) is ______.
ANS:
sp2
12. Refer to Exhibit 1-3. The hybridization of this oxygen atom (B) is ______.
ANS:
sp3
13. Refer to Exhibit 1-3. The hybridization of this carbon atom (C) is ______.
ANS:
sp3
14. Refer to Exhibit 1-3. The hybridization of this carbon atom (D) is ______.
ANS:
sp
15. The molecular formula C2H4O can be converted into three-line bond (Kekulé) structures that
are consistent with valence rules.
a. b. c. d.
a. Which one of the Kekulé structures is not consistent with valence rules?
b. Explain why the structure you chose in part a is not consistent with valence rules.
ANS:
a. d
b. The carbon bonded to the oxygen atom in structure d is pentavalent; it has 10 valence
electrons. Carbon can only have eight valence electrons. In addition, the other carbon
has only six valence electrons when it would prefer to have eight.
3
SHORT ANSWER
1. Give the ground-state electron configuration for carbon (atomic number 6).
ANS:
1s22s22px12py1 or 1s22s22p2
2. Give the ground-state electron configuration for fluorine (atomic number 9).
ANS:
1s22s22px2 2py2 2pz1 or 1s22s22p5
3. Give the ground-state electron configuration for magnesium (atomic number 12).
ANS:
1s22s22p63s2
4. How many electrons does silicon have in its valence shell?
ANS:
four
Exhibit 1-1
Write valid Lewis (electron-dot) structures for each formula below. Show all electrons as dots and
show all non-bonding electrons.
5. C2Cl4 tetrachloroethylene
ANS:
6. CO2 carbon dioxide
ANS:
7. CH4O methanol
1
,Structure and Bonding
ANS:
Exhibit 1-2
Consider the structure of urea, shown below, to answer the following question(s).
8. Refer to Exhibit 1-2. Fill in any non-bonding valence electrons that are missing from the
line-bond structure.
ANS:
9. Refer to Exhibit 1-2. The carbon atom in urea is:
a. sp3 hybridized
b. sp2 hybridized
c. sp hybridized
d. not hybridized
ANS:
b
10. Refer to Exhibit 1-2. The predicted NH2−C=O bond angle in urea is:
a. 109.5°
b. 120°
c. 180°
d. not predictable
ANS:
b
2
, Chapter 1
Exhibit 1-3
Determine the hybridization for the indicated atoms in each structure below.
11. Refer to Exhibit 1-3. The hybridization of this oxygen atom (A) is ______.
ANS:
sp2
12. Refer to Exhibit 1-3. The hybridization of this oxygen atom (B) is ______.
ANS:
sp3
13. Refer to Exhibit 1-3. The hybridization of this carbon atom (C) is ______.
ANS:
sp3
14. Refer to Exhibit 1-3. The hybridization of this carbon atom (D) is ______.
ANS:
sp
15. The molecular formula C2H4O can be converted into three-line bond (Kekulé) structures that
are consistent with valence rules.
a. b. c. d.
a. Which one of the Kekulé structures is not consistent with valence rules?
b. Explain why the structure you chose in part a is not consistent with valence rules.
ANS:
a. d
b. The carbon bonded to the oxygen atom in structure d is pentavalent; it has 10 valence
electrons. Carbon can only have eight valence electrons. In addition, the other carbon
has only six valence electrons when it would prefer to have eight.
3
