CHE 230-001, Fall 2008
Dr. Harris
Name (please print)___________________________________
Student ID #______________________________________
Exam 1 – (5 points each)
1) Draw the Lewis structure of (CH3)2CHCH2CH(CH3)C(CH3)3.
CH3
H3C
CH
H2
C
H3C
H
C
C
CH3
CH3
CH3
2) What is the formal charge on both the N and O?
H
FC(O) = 6 - (6 + 1/2(2)) = -1
C
N
O
FC(N) = 5 - (0 + 1/2(8)) = +1
3) Draw all resonance structures.
O
O
O
O
4) List the orbitals that make up each of the indicated bonds. (For the multiple bonds
describe the orbitals that make up both the sigma and pi bonds)
sp2 - sp3
sp - sp, p-p, p-p
5) Which of the following compounds has a net dipole? Draw the contributing dipoles
of the compound you choose.
(CH3)2CO
6) Draw the product of the following reaction. (Label the Lewis Acid and Base)
+
BASE
B
B
ACID
7) Which molecule is he conjugate acid?
H3O+(aq)
8) Which is the strongest acid? Why?
O
O
OH
OH
S
OH
O
Due to resonance stabilization
SH
9) What intermolecular forces does the following molecule exhibit?
O
O
Van der Waals and dipole-dipole
10) Which of the following has the highest boiling point and why?
largest surface area
11) Label the reactants as either an electrophile or nucleophile. Then if the reaction
occurs, draw the products.
+
O
nucleophile
No reaction
nucleophile
12) Name the following compound.
Cl
1-tert-butyl-2-chloro-4isopropylcycloheptane
13) Which of the following has the highest melting point? Why?
NH2
CH3
Cl
due to stronger
intermolecular forces,
hydrogen bonding
14) Draw the most stable form of trans-1-bromo-4-ethylcyclohexane.
H
Br
H
15) Using Newman projections, draw the most and least stable conformations of pentane
along the indicated bond. (Label them accordingly)
H
CH2CH3
H
H
H3C CH2CH3H
H
H
H
CH3
anti-most
H
H
eclipsed-least
16) Are the following constitutional isomers or stereoisomers?
H
H
H
Cl
Cl
H
H3C
CH3
17) Is the cis or trans isomer of 1-ehyl-4-isopropylcyclohexane lower in energy? (Draw
the chair conformation of each and use them to explain your answer)
H
H
H
H
trans is lower in energy b/c both substituents are in the more stable equatorial positions.
18) Name the following compound.
H
H
H3C
cis-1-isopropyl-3-methylcyclohexane
19) Which of the following is soluble in both organic solvents and water? Why?
O
H3C
CH2
H2C
CH2
H3C
O
NaCl
(CH3)2CO is soluble in organic solvents b/c it's an organic compound and soluble in
water b/c it has 5 or less carbons to each oxygen
20) Name the following compound.
5-cyclopentyl-2,3-dimethylheptane
Final Grade = _____/100 = ______