Chemistry 114
Name______________
Test 1
February 23, 1996
MULTIPLE CHOICE (3 points each) Choose the single, best answer
for each of the following questions.
1. Which of the following matches between class of hydrocarbon and hybridization
is incorrect?
- a. Alkane..................sp3
- b. Alkene..................sp2
- c. Alkyne..................sp
- d. Aromatic................sp3
- e. All are correct.
ANSWER: D -- Aromatic rings are sp2 hybridized.
2. The process of crude oil being separated into various components is known
as
- a. Fractional distillation
- b. Catalytic cracking
- c. Functional group analysis
- d. Depolymerization
ANSWER: A -- Fractional distillation
3. The carbons in the double bond in an alkene have a _______________ geometry.
- a. Linear
- b. Bent
- c. Trigonal planar
- d. Tetrahedral
ANSWER: C -- Trigonal planar
4. The molecule 
is made up of
- a. 3 sigma bonds and 5 pi bonds
- b. 5 sigma bonds and 3 pi bonds
- c. 6 sigma bonds and 2 pi bonds
- d. 7 sigma bonds and 1 pi bond
ANSWER: C -- The triple bond is made of two pi bonds and
one sp-sp sigma bond. The C-C single bond is a sigma bond and the 4 C-H
bonds are sigma bonds.
5. The intermolecular force most prominent in hydrocarbons is
- a. Hydrogen bonding
- b. Charge-charge interactions
- c. Vander Waals interactions
- d. Metallic bonds
ANSWER: C -- Vander Waals interactions
6. Branched hydrocarbons have ____________________ boiling point(s) as the
straight-chained molecules with the same number of carbon atoms.
- a. Lower
- b. The same
- c. Higher
ANSWER: A -- The branching makes for less efficient packing
and thus reduced Vander Waals interactions.
7. Which functional group is not found in the molecule shown below?
- a. Amine
- b. Ether
- c. Ketone
- d. Carboxylic acid
ANSWER: B -- Ether (R-O-R')
8. Which of the following functional groups is found on the molecule
shown below?
- a. Ester
- b. Ketone
- c. Ether
- d. Alcohol
ANSWER: A -- Ester (R-COO-R')
9. Which of the following groups is an isopropyl group?
ANSWER: B -- (A is n-propyl, C is isobutyl, D is tert-butyl)
10. Isoprene is a five carbon precursor for a class of biologically synthesized
molecules know as
- a. Conjugated polyenes
- b. Arenes
- c. Terpenes
- d. Benzenes
ANSWER: C
11. Circle the isoprene units in the following compound.
ANSWER: Isoprene units are shown in bold.
12. Conjugated polyenes and benzene have what features in common?
- a. Same number of carbon atoms
- b. A ring system
- c. Delocalized pi electrons
- d. Triple bonds
ANSWER: C -- Delocalized pi electrons
13. The carbon designated by the arrow in the structure below is a
- a. Primary carbon
- b. Secondary carbon
- c. Tertiary carbon
- d. Quaternary carbon
ANSWER: C -- Tertiary carbon
Name the following structures (3 points each)
14.
ANSWER: 5-ethyl-3,3,5-trimethyloctane
15.
ANSWER: trans-3-tert-butylmethylcyclohexane
16.
ANSWER: 2,4-dibromo-3-chloropentane
17.
ANSWER: 2-ethyl-4-fluoro-3-iodotoluene
18.
ANSWER: 5-methyl-3-heptyne
Draw structures for the following compounds. (3 points each)
19. p-ethylbenzenesulfonic acid
20. 3,4-dimethyl-cis-3-octene
21. 1,1,2,2,3,3-hexabromoheptane
Write the product(s) for the following reactions. (3 points each)
22. 
23. 
24. 
25. 
26. 
27. 
28. 
29. 
30. 
31. The energy as a function of the rotation around the two central carbons
of butane is shown in the graph below.
Also shown are Newman projections for the various conformations of butane.
A B C
D E F
- a. (5 points) Match the Newman projections with the corresponding point
on the energy curve.
ANSWER:
Rotation Angle (degrees) Structure or Structure
0 D D
60 E A
120 B F
180 C C
240 F B
300 A E
- b. (5 points) Give a detailed explanation of your answer for two
of the conformations with different energies.