A molecule with partial charges that readily dissolves in water is described as which?

A molecule with partial charges that readily dissolves in water is described as which?

• A. Nonpolar
• B. Polar
• C. Ionic
• D. Covalent

Answer: (B)

Molecules with partial charges are polar. Unequal sharing of electrons creates a positive end and a negative end, giving the molecule a dipole. Water is itself a highly polar solvent, so it can align with those dipoles and form dipole–dipole interactions and hydrogen bonds. These favorable interactions allow the polar molecule to dissolve readily in water, because the water molecules surround and stabilize the solute. Nonpolar molecules lack significant charge separation, so they don’t interact as strongly with water and don’t dissolve as well. Ionic would imply full opposite charges (ions), not just partial charges, and covalent describes the type of bond rather than solubility; a covalent molecule can be polar or nonpolar, but the key point here is the presence of partial charges. Therefore, the description best matches polar.

Molecules with partial charges are polar. Unequal sharing of electrons creates a positive end and a negative end, giving the molecule a dipole. Water is itself a highly polar solvent, so it can align with those dipoles and form dipole–dipole interactions and hydrogen bonds. These favorable interactions allow the polar molecule to dissolve readily in water, because the water molecules surround and stabilize the solute. Nonpolar molecules lack significant charge separation, so they don’t interact as strongly with water and don’t dissolve as well. Ionic would imply full opposite charges (ions), not just partial charges, and covalent describes the type of bond rather than solubility; a covalent molecule can be polar or nonpolar, but the key point here is the presence of partial charges. Therefore, the description best matches polar.