Which of the following substances has the greatest solubility in C_5H_{12}(l) (pentane) at 1 atm?

• A. NaCl
• B. KNO_3
• C. CH_3OH
• D. CCl_4

Answer: (D)

Verified step by step guidance

1. Identify the nature of the solvent, which is C_5H_{12} (pentane). Pentane is a nonpolar solvent because it is a hydrocarbon with only C-H bonds and no significant polarity.
2. Recall the principle 'like dissolves like,' meaning that polar substances tend to dissolve better in polar solvents, and nonpolar substances dissolve better in nonpolar solvents.
3. Analyze the polarity of each solute: NaCl and KNO_3 are ionic compounds and highly polar, CH_3OH (methanol) is a polar molecule with hydrogen bonding capability, and CCl_4 (carbon tetrachloride) is a nonpolar molecule due to its symmetrical tetrahedral shape and nonpolar C-Cl bonds.
4. Compare the solutes to the solvent: since pentane is nonpolar, the solute with the greatest solubility will be the one that is also nonpolar, which is CCl_4.
5. Conclude that CCl_4 has the greatest solubility in pentane because both are nonpolar, allowing for stronger intermolecular interactions (dispersion forces) between solute and solvent molecules.