,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:
sp3 hybridized
sp2 hybridized
sp hybridized
not hybridized
ANS:
b
10. Refer to Exhibit 1-2. The predicted NH2-C=O bond angle in urea is:
109.5
120
180
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.
Which one of the Kekulé structures is not consistent with valence rules?
Explain why the structure you chose in part a is not consistent with valence rules.
ANS:
d
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:
sp3 hybridized
sp2 hybridized
sp hybridized
not hybridized
ANS:
b
10. Refer to Exhibit 1-2. The predicted NH2-C=O bond angle in urea is:
109.5
120
180
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.
Which one of the Kekulé structures is not consistent with valence rules?
Explain why the structure you chose in part a is not consistent with valence rules.
ANS:
d
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
