A molecule with partial charges that can mix with water is described as which?

A molecule with partial charges that can mix with water is described as which?

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

Answer: (D)

Polarity and how substances interact with water are being tested. A molecule with partial charges is polar because the electrons are not shared equally, giving regions with slight negative and slight positive charge. Water is a polar solvent, so it can surround and stabilize these partial charges through dipole-dipole interactions and hydrogen bonding. That makes polar molecules mix with water, or be hydrophilic. Nonpolar molecules lack those partial charges, so they don’t interact strongly with water and tend to separate. Ionic compounds have full charges (ions), which dissolve via ion-dipole interactions rather than through partial charges. Covalent bonds describe how atoms share electrons; a molecule can have polar covalent bonds and still be polar, but the key clue here is the presence of partial charges, pointing to polarity.

Polarity and how substances interact with water are being tested. A molecule with partial charges is polar because the electrons are not shared equally, giving regions with slight negative and slight positive charge. Water is a polar solvent, so it can surround and stabilize these partial charges through dipole-dipole interactions and hydrogen bonding. That makes polar molecules mix with water, or be hydrophilic.

Nonpolar molecules lack those partial charges, so they don’t interact strongly with water and tend to separate. Ionic compounds have full charges (ions), which dissolve via ion-dipole interactions rather than through partial charges. Covalent bonds describe how atoms share electrons; a molecule can have polar covalent bonds and still be polar, but the key clue here is the presence of partial charges, pointing to polarity.