CHAPTER 2- Practice Exercises (ORGANIC CHEM I )________DR. PAHLAVAN
1. Ephedrine- commonly used as a stimulant, appetite suppressant, concentration aid, decongestant, and to
treat hypotension associated with anaesthesia. Calculate the formal charge of the indicated atoms.
d
c
b
O
O
H3N
NH
a
O
O
e
f
O
1. Using partial charges ( + /   ), indicate the polarity (
following:
) of the polar covalent bonds in the
F
Cl
H
O
O
C = C
F
F
H
Cl
(a)
(b)
(d)
(c)
2. Which of the following pairs represent resonance structures?
and
(a)
(b) CH3 - CH = CH - CH3 and H2 C = CH - CH2 - CH3
..
:O:
O
(c) CH3 - C - CH
.. 2
and CH3 - C = CH2
(e) H3C - N = N = N :
and
H3C - N - N
(d) : N - N
N:
N=N=N
and
N:
3. Draw all possible resonance structures for the species below:
: O:
:O:
..
(b) CH3 - C - CH = CH CH2
(a)
(d)
(c)
5. (I) Circle all the Lewis bases and box all the Lewis acids in the group of compound below:
CH3
I
BCl3
FeBr3
H3O
: NH3
CH3OH
Br
+
N
..
(II) Label the acid and the base in each reaction below:
(a) CH3OH + NaH
CH3O Na
+ H2
(b) CH3 O CH3 + BH3
..
H3C - O - CH3
BH3
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6. Write a conjugate acid and a conjugate pairs for each of the followings.
a) H2O
7.
c) HS
b) NH3
d) HSO4
d) CH3OH
e) H2PO4
f) HC2
a) Given that pKa for phenol is 9.95 and pKa for ammonium ion is 9.25. Will the following reaction
occur? Will the reactant or the product be favored at equilibrium?
OH
O
?
+ NH3
+ NH4
phenoxide ion
b) Given the following reaction, indicate acid and base on both sides of the equilibrium.. Also indicated
on which side the equilibrium would lie.
:
N
C-H +
:
N
C:
+
N
N
pKa = 9.1
pKa = 5.2
H
9. Determine the number of hydrogen bonded to the indicated atoms using the following skeletal structures
shown below, which is the molecular formula for cocaine.
d
c
b
e
O
O
H3N
NH
a
g
O
O
f
O
10. Convert the following structures into molecularformulas.
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