2. Molecular Representations

Predict which member of each pair is more soluble in water. Explain your prediction.

(c)

(d)

Methoxychlor is an insecticide that was intended to take DDT’s place because it is not as soluble in fatty tissues and is more readily biodegradable. It, too, can accumulate in the environment, however, so its use was also banned—in 2002 in the European Union and in 2003 in the United States. Why is methoxychlor less soluble in fatty tissues than DDT?

In which solvent would cyclohexane have the lowest solubility: 1-pentanol, diethyl ether, ethanol, or hexane?

Rank the following molecules from least water soluble to most water soluble. Explain your reasoning.

(a) H₃C ― OH

Predict which member of each group is most soluble in water, and explain the reasons for your predictions.

b. chlorocyclohexane, cyclohexanol, or cyclohexane-1,2-diol

In each pair,

(i) choose the compound that is most soluble in water.

(ii) Within each pair, which is most soluble in nonpolar solvents?

(a)

Classify the following molecules as hydrophilic, hydrophobic, lipophilic, or lipophobic. Each molecule should have two classifications.

(a)

Classify the following molecules as hydrophilic, hydrophobic, lipophilic, or lipophobic. Each molecule should have two classifications.

(d)

Rank the given solvents in decreasing order of their ability to dissolve each compound.

Solutes:

(a) NaOAc

(b)

(c)

Solvents:

ethyl ether

water

ethanol

dichloromethane

Classify the following molecules as hydrophilic, hydrophobic, lipophilic, or lipophobic. Each molecule should have two classifications.

(b)

Rank the following molecules from least water soluble to most water soluble. Explain your reasoning.

(b) LiCl

Which of the following reactions would benefit from micellar technology (Figure 7.10), allowing them to be run in water?

(a)

(b)

(c)

The effectiveness of a barbiturate as a sedative is related to its ability to penetrate the nonpolar membrane of a cell. Which of the following barbiturates would you expect to be the more effective sedative?

Explain why amino acids, unlike most amines and carboxylic acids, are insoluble in diethyl ether.

Ansaid and Motrin belong to the group of drugs known as nonsteroidal anti-inflammatory drugs (NSAIDs). Both are only slightly soluble in water, but one is a little more soluble than the other. Which of the drugs has the greater solubility in water?