Which type of solute is most strongly attracted to water molecules due to intermolecular forces?

• A. Hydrophobic polymers such as polyethylene
• B. Noble gases such as argon (Ar)
• C. Ionic compounds such as NaCl
• D. Nonpolar molecules such as methane (CH_4)

Answer: (C)

Verified step by step guidance

1. Understand that water is a polar molecule with a significant dipole moment, which means it can interact strongly with other polar or charged species through intermolecular forces such as hydrogen bonding and ion-dipole interactions.
2. Recognize that ionic compounds like NaCl dissociate into ions (Na⁺ and Cl⁻) in water, and these ions are strongly attracted to the partial positive and negative charges on water molecules, forming ion-dipole interactions.
3. Contrast this with hydrophobic polymers such as polyethylene, which are nonpolar and do not have charges or dipoles to interact strongly with water; thus, they are not strongly attracted to water molecules.
4. Note that noble gases like argon are nonpolar atoms with very weak London dispersion forces and do not interact strongly with polar water molecules.
5. Understand that nonpolar molecules such as methane (CH₄) also lack polarity and cannot form strong interactions with water, making them less attracted to water compared to ionic compounds.