Multiple Choice –Choose the best answer for the following:
1. Which forms the most stable carbocation?
Cl
I
Cl
a.
b.
c.
Br
I
d.
e.
2. Put these compounds in order of decreasing SN2 reaction rate (left to right).
CH3CH2CH2Cl
1
CH 3
|
CH 3 CHCH 2 Cl
Cl
|
CH 3CH 2 CHCH
2
CH 3
|
CH 3 CCl
|
CH 3
3
3
4
a. 1, 2, 3, 4
b. 4, 3, 2, 1
c. 1, 2, 4, 3
d. 3, 4, 2, 1
e. 3, 2, 4, 1
3. Which is most reactive in an SN1 reaction?
I
I
CH3I
a.
b.
I
c.
d.
I
e.
4.What is the equation for the rate of formation of 2-methoxypropane, CH3CH(OCH3)CH3, from
the reaction of 2-bromopropane (i-PrBr) with sodium methoxide (NaOCH3)?
a. Rate = k [i-PrBr]
b. Rate = k [i-PrBr]2
c. Rate = k [NaOCH3]
d. Rate = k [i-PrBr][NaOCH3]
5. The reaction of tert-butyl chloride, (CH3)3CCl, with water in an inert solvent gives tert-butyl
alcohol, (CH3)3COH. What is the effect of doubling the concentration of water on the rate of the
reaction?
a. the rate remains the same
b. the rate decreases by a factor of 2
c. the rate increases by a factor of 2
d. the rate increases by a factor of 4
6.What is the major organic product obtained from the following reaction?
OH
H2SO4
1
2
SH
3
4
a. 1
b. 2
c. 3
d. 4
7. Which of the following best describes the C-Cl bond of an alkyl chloride?
A. non polar, no dipole
B. polar, δ+ at carbon and δ- at chlorine
C. polar; δ- at carbon and δ+ at chlorine
D. ionic
E. none of the above
8. Which is the best leaving group for nucleophilic substitution?
a. TsO–
b. CH3CO2–
c. –Cl
d. –NO2
e. –F
9. Which of the following sets consists of only polar aprotic solvents?
a. water, hexane, methanol
b. acetic acid, DMF, toluene
c. DMSO, ethanol, acetonitrile
d. DMF, acetonitrile, DMSO
10. Which of the following sets consists of only polar protic solvents?
a. water, DMF, DMSO
b. acetic acid, methanol, water
c. DMSO, ethanol, acetonitrile
d. DMF, acetonitrile, DMSO
11. Which of the following most favors elimination rather substitution in a reaction with sodium
methoxide?
a. bromomethane
b. bromoethane
c. 1-bromopropane
d. 2-bromopropane
12. What is the major organic product obtained from the following reaction?
O
H3C
S
1
O
OH
O
Cl
S
Cl
2
pyridine
O
O
S
O
4
3
a. 1
b. 2
c. 3
d. 4
13. What is the major organic product obtained from the following reaction?
SH
OH
a. 1
b. 2
c. 3
H2SO4
CH3
1
2
3
4
CH3
d. 4
14. Which is the major expected product of this reaction?
CH 3
–
Cl
OH
CH 3
CH 2
CH 3
OH
a.
b.
c.
CH 3
CH 3
OH
d.
e.
Part II
1. Provide a mechanism for the following:
2.