Updated
SCI 2399 - Spring 2017 - Chapter 5
Homework 5
(Chapter 5: Reactions of alkenes and alkynes)
_________________________________________________________________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the
question.
1) What is the hybridization of the carbon atoms numbered 1 and 2 respectively in
the following structure?
A) sp2, sp2
B) sp3, sp2
C) sp2, sp
D) sp, sp2
1)
E) sp, sp
2) Among the compounds water, 1-butyne, 2-butyne, and ethane, which are
stronger acids than ammonia?
A) 1-butyne and ethane
B) 1-butyne and 2-butyne
C) water and 1-butyne
D) water and ethane
2)
3) What is the major product in the following reaction?
3)
A) I
B) II
C) III
D) IV
1
E) V
Updated
4) Which of the following improperly describes the physical properties of an
alkyne?
A) less dense than water
B) relatively nonpolar
C) nearly insoluble in water
D) insoluble in most organic solvents
4)
5) How many distinct internal alkynes exist with a molecular formula of C6H10?
A) 1
B) 2
C) 3
D) 4
E) 5
5)
6) How many electrons are involved in a carbon-carbon triple bond?
A) 1
B) 2
C) 3
D) 4
6)
7) Which of the following alkenes reacts with HCl at the slowest rate?
A)
B)
C)
D)
E)
2
E) 6
7)
Updated
8) The reagent needed to convert 2-butyne to cis-2-butene is:
A) Na/NH3
B) Li/NH3
C) H+/Zinc dust
D) H2/Lindlar's catalyst
E) H2/Pt
8)
9) A mixture of 1-heptyne, 2-heptyne, and 3-heptyne was hydrogenated in the
presence of a platinum catalyst until hydrogen uptake ceased. If one assumes
that the hydrogenation went to completion, how many distinct seven-carbon
hydrocarbons were produced?
A) 1
B) 2
C) 3
D) 6
E) 8
9)
10) What is the general formula for a noncyclic alkyne?
A) CnH2n-4
B) CnH2n-2
C) CnH2n
D) CnH2n-1
E) CnH2n+2
10)
11) Which of the following is the most stable carbocation?
11)
A) I
B) II
C) III
D) IV
3
E) V
Updated
12) What is the IUPAC name for the following alkyne?
12)
A) 2-Bromomethyl-4-hexyne
B) 3-Bromo-5-heptyne
C) 5-Bromo-5-methyl-2-hexyne
D) 5-Bromo-2-heptyne
E) 5-Bromo-5,5-dimethylhexyne
13) What is the common name for the following alkyne?
13)
A) tert-Butylacetylene
B) Neohexyne
C) Trimethylpropyne
D) Trimethylacetylene
E) Isopropylacetylene
14) What are the hybridizations of the carbon atoms numbered 1 and 2 in the
structure below?
1 2
H3C-CHCH-CC-H
A) sp2, sp2
B) sp2, sp
C) sp3, sp2
D) sp, sp
15) Which of the following compounds will react most rapidly with HCl?
A) (E)-5-methyl-2-hexene
B) 2-methyl-2-hexene
C) (E)-2-methyl-3-hexene
D) 4-methyl-1-hexene
E) 5-methyl-1-hexene
4
14)
15)
Updated
16) What two atomic orbitals or hybrid atomic orbitals overlap to form the
carbon-carbon σ bond in ethyne?
A) pp
B) spsp
C) ss
D) sp2sp2
E) sp3sp3
16)
17) Which of the following reagents gives the reaction shown below?
17)
CH3CH=CH2 +
A) H2/Ni
B) H2/HCl
C) H2O/Ni
D) H2O/H2SO4
E) H2/H2SO4
?
→
CH3CH2CH3
18) How many distinct terminal alkynes exist with a molecular formula of C5H8?
A) 1
B) 2
C) 3
D) 4
E) 5
18)
19) Which of the following are correct statements concerning unsaturated
hydrocarbons?
A) All unsaturated hydrocarbons are soluble in nonpolar solvents.
B) All unsaturated hydrocarbons are insoluble in water.
C) All unsaturated hydrocarbons are more dense than water.
D) A and B
E) A, B, and C
19)
20) What is the major product from the acid-catalyzed hydration of
2-methyl-2-pentene?
A) 1-methoxypentane
B) 2-methylpentane
C) 2-methyl-3-pentanol
D) 2-methyl-2-pentanol
E) 2-methyl-1-pentanol
20)
5
Updated
21) Which of the following is a correct statement about the carbon-carbon triple
bond in an alkyne?
A) composed of two sigma bonds and one pi bond
B) composed of one sigma bond and two pi bonds
C) composed of one sigma bond and one pi bond
D) composed of one sigma bond, one pi bond and one delta bond
E) composed of two sigma bond and two pi bond
6
21)