A substance that is soluble only in nonpolar solvents and does not conduct electricity is best described as

• A. An ionic substance
• B. A polar substance
• C. A nonpolar substance
• D. A metallic substance

Answer: (C)

The key idea is how polarity affects both solubility and conductivity. Nonpolar substances interact best with nonpolar solvents through dispersion forces, so they dissolve in nonpolar solvents rather than in polar ones. If a substance doesn’t ionize in solution, there are no mobile charged particles to carry electric current, so it won’t conduct electricity. Put together, these properties point to a nonpolar substance. An ionic substance would conduct when dissolved and typically wouldn’t be soluble only in nonpolar solvents; a polar substance often dissolves in polar solvents; a metallic substance conducts due to free electrons, not because of this solubility pattern.