Chapter 4 Study Guide Key
Interactive Questions
4.1 Identify the structural isomers, geometric isomers, and enantiomers from the following
compounds. Which of the geometric isomers is the cis isomer?
Ethanol and dimethyl ether, structural isomers, have the same number and kinds of atoms but a
different boding sequence and very different properties. Maleic acid and fumaric acid are
geometric isomers whose double bonds fix the spatial arrangement of the molecule. Maleic acid
is the cis isomer; both non-hydrogen groups are on the same side of the double bond. Although
the enantiomers L- and D-lactic acid look similar in a flat representation of their structures, they
are not superimposable.
Suggested Answers to Structure Your Knowledge
1.
Isomers
Have same
Molecular
formulae
Have different
Molecular
shapes
Chemical
properties
Due to
May be
Structural
isomers
Geometric
isomers
enantiomers
Have different are
Different
Have different
arrangement of
Spatial
arrangements
Atoms and
double bonds
Due to
Due to
No rotation around
double bond
Different threedimensional shapes
Mirror
images
Places of atoms around
asymmetric carbon
2.
Functional Group
Hydroxyl
Carbonyl
Carboxyl
Amino
Sulfhydryl
Phosphate
Molecular
Formula
-OH
=C=O
-COOH
-NH2
-SH
-OPO32-
Names and Characteristics of Organic
Compounds Containing Functional Group
Alcohols; polar group
Aldehyde or ketone; polar group
Carboxylic acid; release H+
Amines; basic, accept H+
Thiols; cross-links stabilize protein structure
Organic phosphates; used in energy
transfers, acidic
Answers to Test Your Knowledge
Multiple Choice
1. c; its four electrons in the valence shell that can form four covalent bonds. (p60)
2. b; the C-H bond is nonpolar. (p62)
3. e; It can be a part of geometric isomers. (p62)
4. a; mechanism (p59)
5. d; -NH2 (p64)
6. a; -COOH (p64)
7. d; They are a result of restricted movement around a carbon double bond. (p62)
8. d; hydrocarbons (p61)
9. c; 3 (p62)
Matching (refer to pages 64-65)
1. a, c
2. b, f
3. a, d, e
4. e
5. e
6. a, c, d, e
7. bf
8. e
9. ac
10. a, d
11. e
12. c