H
CH
3
H
CH
3
H
HCH
3
CH
3
H
H
H
H
Chem 2411
Clower
Alkane Physical Properties and Conformations
1. Draw the lowest energy Newman projection of hexane (looking down the C3-C4 bond).
2. Which of the following statements concerning the conformations of butane is true?
A. All butane conformations are classified as eclipsed.
B. The lowest energy conformation of butane is the gauche conformation.
C. The gauche and anti conformations differ primarily in the amount of steric strain.
D. There is more torsional strain in the anti conformation than in the totally eclipsed
conformation.
3. Determine whether the two structures in each of the following pairs represent constitutional
isomers, geometric isomers (cis, trans), or different conformations of the same compound.
(a)
(b)
(c)
4. Rank the following molecules in order of increasing boiling point (lowest to highest).
CH3CH2CH2CH2CH3CH3CH2CH(CH3)2C(CH3)4CH3CH2CH2CH2OH
H
CH
3
H
H
CH
3
CH
3
CH
3
H
CH
3
CH
2
H
H
H
