2. Molecular Representations

Would you expect the following molecule to be miscible in an aqueous solution?

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

(a)

(b)

Circle the member of each pair that is more soluble in water.

a. CH₃CH₂OCH₂CH₃ or CH₃CH₂CH₂CH₂CH₃

b. CH₃CH₂OCH₂CH₃ or CH₃CH₂CH₂OH

c. CH₃CH₂NHCH₃ or CH₃CH₂CH₂CH₃

d. CH₃CH₂OH or CH₃CH₂CH₂CH₂OH

e.

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

(e)

(f)

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