Structural Representations
Major Concepts
 Because of typical bonding patterns, it is possible to draw structures with implicit assumptions
 Condensed structures and bond-line structures are fast ways to convey bonding information
 Saturated compounds contain the maximum number of hydrogen atoms, but unsaturated
compounds contain multiple bonds
Vocabulary
 Condensed formula
 Bond-line formula
 Implicit
 Saturated and unsaturated compounds
Students should be able to:
 Convert between various bonding representations
 Recognize drawings with incorrect angles
 Draw constitutional isomers of unsaturated compounds
 Determined implicit information (H’s, lone pairs) in bond-line formula of typically bonded
compounds
Daily Problems
1. Do problems 1-24 in chapter 1 of Organic as a Second Language.
2. Convert the following Lewis structures into condensed formulas.
3. Convert the following condensed formulas into Lewis structures. (Be sure to include all lone pairs.)
a. (CH3)2CHCH2CH2Cl
b. CH3(CH2)4NHCH3
c. CH2=CHCH2CH(CH3)2
4. Fill in the missing Lewis structure, condensed structure, and/or bond line formula for these
compounds.
Lewis structure
Condensed structure
H
H
C
C
C
H
H
H
Bond-line formula
H
O
C
H
CH2CHCH2OCH3
H
H
N
C4H7N
CH3CH2O(CH2)3CH3
(CH3)2CHCH=CHCH3
H
H
H
C
C
H
C
H H
C
C
H
H
O=CHCH2CH2CH3
5. A C5H10 compound does not have the maximum number of hydrogen atoms in its formula. According
to the CnH2n+2 rule, the maximum number of hydrogen atoms is 12 . It has two less, which means that
it has one degree of unsaturation, which could either be a ring or a double bond. Draw bond-line
drawings for all the constitutional isomers of C5H10 that you can. (At this point, you should be able to get
nine distinct compounds.)
6. Redraw these badly drawn bond-line structures.
Cumulative Problems
7. Draw all constitutional isomers for these compounds. (They may be saturated or unsaturated, so
figure that out first.)
A. C3H7F (0 unsaturations)
B. C3H5Br (1 unsaturation)
C. C3H6O (1 unsaturation)
8. Indicate any atom in these structures that does not have typical bonding
Extension problems
9. Redraw the compounds in problem 8, explicitly drawing all lone pairs. Consider the atoms you
marked as not having typical bonding—do they have more or less electron associated with them than
typical? (Consider bonding electrons as being “shared” and therefore not completely belonging to
either atom of the bond.)