Chemistry 201-01
Hour Examination I
20 September 2002
Name_____Dr. Price________
Answer all of the questions in the spaces provided. Point values are in parentheses. Be
sure to read the questions carefully.
1.(15) Propose the best possible Lewis-dot structures for the following species. Use
lines for covalent bonds, show any formal charges where appropriate, and indicate the
hybridization of each atom other than hydrogen or halogen.
a) C2O2Cl2
sp2
O
Cl
sp2
C
C
c) HNO2
sp3
b) CHO2
sp2
O
Cl
H
O
C
sp2
H
O
O
sp2
N
sp2
O
best with
no formal charges
sp3
2.(10) For the following reactions identify the acid, base and both conjugate species.
Also determine whether or not the reaction proceeds to the right as written. (pKa values
in general: alcohols 15-18; alkanes 49-55; carboxylic acids 4-6; phosphoric acid 2.)
OLi
OH
a) (CH3)3CLi +
base
+ (CH3)3CH
acid
c.b.
O
COH
b)
c.a.
O
COK
+ KH2PO4
acid
base
+ H3PO4
c.b.
c.a.
3.(10) Draw the resonance structure for each of the species below using the arrows
indicating the electron flow.
O
O
a)
b)
4.(12) Identify and name all of the functional groups in aspartame (Nutrasweet) and
Effexor® (antidepressant Vanlafaxine) shown below:
amide
amine
O
CH3
CH3
OH N amine
alcohol
O
H2NCHCNHCHCOCH3
ester
CH2
HOCCH2
carboxylic acid
O
arene
arene
ether
Aspartame
OCH3
Venlafaxine
5.(12) The molecule shown below is an extremely unusual, unstable and unsaturated
hydrocarbon. In the diagram below, identify all orbitals (e.g. px, sp2) and bond types (e.g.
π, σ). Additionally, propose a Lewis structure (lines for all bonds) for this hydrocarbon.
py
sp2
sH
Hs σ
C
π
σ
sp2 sp
pz
py
σ
σ H
C sp sp2 C
sp2 s
pz
π
σ H
H
H
H
C
C
C
H
6.(15) Using Kekulé structures (zig-zag), draw 7 unique structural isomers with the
formula of C7H16. There are 9 possible isomers.
7.(16) Give the names for the following compounds using I.U.P.A.C. nomenclature.
8
1
7
2
6
a) (CH3)2CH(CH2)3CH(CH3)2
b)
5 3
4
2,6-dimethylheptane
c)
CH2CH2CH2Cl
CH3CHCH2CH2CCH3
CH3CHCH3
5-ethyl-3,5-dimethyloctane
d)
CH2CH3
Cl
1,4-dichloro-4,7,8-trimethylnonane
CH2CH3
cis 1,4-diethylcytclobutane
8.(10) Compare BF3 and BH3. Which do you suppose is the stronger Lewis acid. Draw
accurate depictions of both structures (make sure the bond angles are reasonable) and
explain why you feel one is a stronger Lewis acid than the other.
very small bond moments
H
H
B
F
H
F
B
F
Both are Lewis acids but BF3 is stronger
because the Boron is more electron-deficie
thus its empty p orbital is more likely
to act as an electron-pair acceptor.
Draw the product of the Lewis acid-base reaction between boron trifluoride and
ammonia.
F
BF3 + NH3
F
B
F
N
H
H
H