Deck 8: Nomenclature and Noncovalent Intermolecular Interactions

Question 1

Provide a systematic name for the compound, including any stereochemical designations.

Answer 1

(4S,5R)-5-methoxy-1-hepten-4-ol

Question 2

Name the compound with an IUPAC systematic name.

Answer 2

4-butyl-1-chloro-4-penten-2-ol (or 4-butyl-1-chloropent-4-en-2-ol)

Question 3

Select the structure of the compound with the highest boiling point.

A) compound a
B) compound b
C) compound c
D) compound d

Answer 3

D

Question 4

When DMSO dissolves potassium chloride (K⁺ Cl⁻), what is the solvation of the salt due to?

A) The charge-dipole interaction of the sulfur with the K⁺.
B) The charge-dipole interaction of the oxygen with the K⁺.
C) The charge-dipole interaction of the oxygen with the Cl⁻.
D) The hydrogen-bonding interaction of the chloride ion with the C-H bonds.

Question 5

When two hydrocarbon molecules (such as hexane), initially dissolved in water, come together to form an aggregate in water, two of the following are true.

A) The process has ΔG° > 0.
B) The process has ΔH° << 0.
C) The free energy of the process is dominated by the negative entropy of mixing.
D) The process has TΔS° > 0.
E) The process has ΔG° < 0.

Question 6

Dissolving hexane in water has

A) a large negative ∆S°.
B) a large positive ∆S°.
C) a large negative ∆G°.
D) a large negative ∆H°.
E) a large positive ∆H°.

Question 7

The boiling point of pentane is 36 °C. The compound with the highest boiling point is

A) water (bp = 100 °C).
B) octane.
C) nonane.
D) 2,2,4,4-tetramethylpentane.
E) methanol.

Question 8

Sodium chloride, an ionic compound, should be most soluble in which solvent? ( = dielectric constant)

A) compound a
B) compound b
C) compound c
D) compound d
E) compound e

Question 9

Arrange these compounds in order of increasing boiling point (lowest boiling point first).

A) A < B < C < D
B) B < C < D < A
C) D < A < C < B
D) D < A < B < C

Question 10

In each case, identify the better solvent for dissolving the compounds. Choose between H₂O (ε = 78) or benzene (ε = 2.3). (Benzene is a six-carbon cyclic hydrocarbon.)

Question 11

By circling three items below each structure, classify each of the following solvents as polar or apolar, donor or nondonor, protic or aprotic.

Question 12

Which compound would form the strongest complex with potassium ion?

A) compound A
B) compound B
C) compound C
D) compound D

Question 13

In which solvent should NaCl (an ionic compound) have the greatest solubility? (ε = dielectric constant.) Explain your choice briefly.

Question 14

Until the FDA rescinded the permit for its use in 2002, perflubron, a mixture of 1-bromoperfluorooctyl bromide [CF₃(CF₂)₆CF₂Br] and 1-bromoperfluoroodecyl bromide [CF₃(CF₂)₈CF₂Br], was being investigated for possible use as artificial blood during surgery. Perflubron dissolves substantial amounts of oxygen; a mouse can breathe when submerged in oxygenated perflubron. Perflubron is completely insoluble in water. To make it compatible with the aqueous biological environment, it had to be suspended in water in such a way that it would form an emulsion and not separate into layers. (In an emulsion, water-insoluble substances are suspended as small particles that do not form a separate layer.) Addition of lecithin, a phospholipid from egg yolks, met this objective.
Explain the action of lecithin. As part of your explanation, use a diagram to propose a general structure of a perflubron-containing particle.

Question 15

Draw the structure of 3-hexyn-2-ol.

Question 16

Name the compound. Include the appropriate stereochemical designation in the name.

Question 17

Name the compound. Include the appropriate stereochemical designation in the name.

Question 18

Draw the structure of 3-ethoxy-2-butanethiol (alternate name 3-ethoxybutane-2-thiol).

Question 19

Given four compounds with the same branching pattern and similar molecular masses, which compound has the highest boiling point?

A) compound A
B) compound B
C) compound C
D) compound D

Question 20

Which structure has the lowest melting point of the various 18-carbon fatty acids given?

A) compound A
B) compound B
C) compound C
D) compound D

Question 21

Consider the equilibria in CCl₄, an apolar, aprotic, nondonor solvent.
Explain why replacing the two carbons of the ring shown above with oxygens makes the axial conformation more stable.

Question 22

Compounds consisting of molecules that can both donate and accept hydrogen bonds have higher boiling points than isomeric compounds that cannot donate hydrogen bonds because

A) hydrogen bonding increases molecular stability.
B) hydrogen bonding decreases molecular stability, and less-stable molecules have a greater tendency to escape from solution.
C) hydrogen bonding between molecules lowers the vapor pressure, so a higher temperature is required to increase the vapor pressure to atmospheric pressure.
D) hydrogen bonding increases water solubility.

Question 23

Drugs are often conjugated to glucuronic acid groups in biological systems. Explain why you would need to conjugate a drug to glucuronic acid and how glucuronides solve this problem.

Question 24

This is the predominant form of the sugar D-glucose.
Glucose does not passively cross cell membranes, even though it is a neutral molecule. Explain why.

Question 25

Draw all the alcohols having a molecular formula of C₄H₁₀O.
a. Indicate if the alcohol is chiral.
b. Name each alcohol using IUPAC nomenclature.
c. Classify each alcohol as primary, secondary or tertiary.