Based only on intermolecular forces, which of the following compounds would be the least soluble in CH3CH2OH (ethanol)?

• A. H2O
• B. CH3COOH
• C. CH3NH2
• D. CCl4

Answer: (D)

Verified step by step guidance

1. Step 1: Identify the type of solvent and its intermolecular forces. Ethanol (CH3CH2OH) is a polar molecule that can form hydrogen bonds due to its -OH group, so it primarily exhibits hydrogen bonding and dipole-dipole interactions.
2. Step 2: Analyze the intermolecular forces present in each solute: H2O (water) is highly polar and can form strong hydrogen bonds; CH3COOH (acetic acid) is polar and can also hydrogen bond; CH3NH2 (methylamine) is polar and capable of hydrogen bonding; CCl4 (carbon tetrachloride) is nonpolar and only exhibits London dispersion forces.
3. Step 3: Apply the principle 'like dissolves like,' which means polar solvents dissolve polar solutes well, especially those capable of hydrogen bonding, while nonpolar solutes dissolve poorly in polar solvents.
4. Step 4: Compare the solutes to ethanol: since H2O, CH3COOH, and CH3NH2 can all hydrogen bond and are polar, they will be more soluble in ethanol, whereas CCl4, being nonpolar and unable to hydrogen bond, will be the least soluble.
5. Step 5: Conclude that based on intermolecular forces, CCl4 is the least soluble in ethanol because it lacks polarity and hydrogen bonding capability, making it incompatible with ethanol's polar nature.