CHEM 110
--------------------------------------------------------------------------------------------------------------------1. Which of the following molecules are structural isomers?
3
4
1
2
--------------------------------------------------------------------------------------------------------------------2. Which one of the following molecules is the
geometrical isomer of cis-3,4-dimethyl-3-hexene
shown at the right?
cis-3,4-dimethyl-3-hexene
B
A
C
Follow-up: Which of the answer choices
CANNOT have a geometric isomer?
(If a molecule can have a geometric isomer,
D
can you draw it?)
E
--------------------------------------------------------------------------------------------------------------------3. What functional groups are present in the following molecules?
OH
O
O
N
N
N
N
O
O
A. carvone
(spearmint oil)
B. caffeine
C. Testosterone
(steroid)
CH3
CH3
O
O
H2N
HO
O
C
O
O
OH
O
C
H
C
CH2
OH
HO
C
C
CH
N
C
H2
H
F. aspartame
artificial sweetener
D. estradiol (Estrogen)
(steroid)
E. oxybenzone
sunscreen
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Recitation 8
CHEM 110
-----------------------------------------------------------------------------------------------------------------4. List the intermolecular forces that are important for each of these molecules.
I.
CaCl2
IV.
CH3COOH
II.
HBr
V.
NH3
III. CH3CH3
-----------------------------------------------------------------------------------------------------------------5. What properties of H2O can be attributed to hydrogen bonding?
I.
Liquid water is colorless.
II.
The density of ice is lower than that of liquid water.
III.
Water has a higher boiling point than H2S.
-----------------------------------------------------------------------------------------------------------------6. Which pairs of molecules have the correct boiling point (bp) trend?
i.
bp of CS2 > bp of CO2
ii
bp of O2 > bp of H2
iii
bp of SiH4 > bp of SnH4
-----------------------------------------------------------------------------------------------------------------7. Rank the following in order of increasing boiling point. (Be sure that you can explain WHY
this trend exists.)
OH
O
OH
O
3. C4H10O
2. C5H12
1. C3H6O2
4. C4H10O
----------------------------------------------------------------------------------------------------------------------------8. Arrange the following in order of decreasing melting point.
CaO
Ar
H 2O
-----------------------------------------------------------------------------------------------------------------9. Which of these molecules is/are polar?
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
Cl
I
II
III
IV
-----------------------------------------------------------------------------------------------------------------10. Draw a structural formula for CH2Cl2, not worrying about molecular shape. If this molecule
were planar, with bond angles of 90°, how many isomers would there be? If it is tetrahedral,
with bond angles of 109.5°, how many isomers are there?
----------------------------------------------------------------------------------------------------------------------------11. Write all the isomers you can that have the formula C6H12. (Don’t forget cycles.)
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Recitation 8