Which statement about polar molecules is correct?

• A. Polar molecules have no partial charges.
• B. Polar molecules are always nonpolar solvents.
• C. Polar molecules cannot interact with water.
• D. Polar molecules have partial charges and mix with water.

Answer: (D)

Polar molecules have partial charges because electrons aren’t shared evenly within the molecule, creating a positive region and a negative region. This separation of charge gives the molecule a dipole moment, so it can interact strongly with water, a highly polar solvent. Water’s molecules can align themselves around the polar solute and form favorable dipole-dipole and hydrogen-bonding interactions, which helps dissolve the polar molecule. That’s why a statement saying polar molecules have partial charges and mix with water is correct.

The other statements contradict what polarity means. If a molecule had no partial charges, it wouldn’t be polar. Saying polar molecules are always nonpolar solvents is incorrect because polar substances can and do dissolve in water. And claiming polar molecules cannot interact with water runs against the idea that polarity drives interaction with water through hydrogen bonds and dipole interactions.