Which solvent would best dissolve a polar solute?

Which solvent would best dissolve a polar solute?

• A. Hexane
• B. Water
• C. Oxygen gas
• D. Nitrogen gas

Answer: (C)

Polar solutes dissolve best in polar solvents because the solvent molecules can stabilize the solute’s dipoles through dipole–dipole interactions and hydrogen bonding. Water, being highly polar and capable of extensive hydrogen bonding, interacts strongly with polar solutes, helping to separate solute particles and surround them with solvent molecules. Nonpolar solvents like hexane offer little attraction to polar solutes, so they don’t effectively disrupt the solute–solute forces. The diatomic gases oxygen and nitrogen are also nonpolar and don’t provide the needed solvent–solute interactions for polar substances. Therefore, water is the most effective solvent for dissolving a polar solute.

Polar solutes dissolve best in polar solvents because the solvent molecules can stabilize the solute’s dipoles through dipole–dipole interactions and hydrogen bonding. Water, being highly polar and capable of extensive hydrogen bonding, interacts strongly with polar solutes, helping to separate solute particles and surround them with solvent molecules. Nonpolar solvents like hexane offer little attraction to polar solutes, so they don’t effectively disrupt the solute–solute forces. The diatomic gases oxygen and nitrogen are also nonpolar and don’t provide the needed solvent–solute interactions for polar substances. Therefore, water is the most effective solvent for dissolving a polar solute.