Question

Which among the following compounds is most soluble in water?

• A. Ethanol
• B. Ethane
• C. Phenol
• D. Ethylene glycol

Answer 1

The Correct Option is D

Water solubility is determined by molecular structure and hydrogen bonding potential. Compounds capable of forming hydrogen bonds with water exhibit increased solubility.

1. Ethanol (C₂H₅OH): Possesses an -OH group that facilitates hydrogen bonding, contributing to moderate solubility.
2. Ethane (C₂H₆): A nonpolar molecule lacking hydrogen bonding capacity, leading to limited solubility.
3. Phenol (C₆H₅OH): Features an -OH group, but its solubility is reduced by the presence of a substantial nonpolar benzene ring.
4. Ethylene glycol (C₂H₄(OH)₂): Contains two -OH groups, enabling extensive hydrogen bonding and consequently high solubility.

Ethylene glycol demonstrates the highest water solubility among the listed compounds due to its two hydroxyl groups, which promote multiple hydrogen bonds with water molecules and thus enhance its solubility.