When an O_2 molecule approaches an H_2O molecule, what happens to the end of the O_2 molecule that is closest to the positive (hydrogen) end of the H_2O molecule?

• A. It remains completely unaffected because O_2 is nonpolar.
• B. It forms a covalent bond with the hydrogen atom of H_2O.
• C. It becomes slightly positively charged due to electron repulsion.
• D. It becomes slightly negatively charged due to induced dipole interaction.

Answer: (D)

Verified step by step guidance

1. Recognize that water (H_2O) is a polar molecule with a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom due to its bent shape and electronegativity differences.
2. Understand that oxygen (O_2) is a nonpolar molecule because it consists of two identical oxygen atoms sharing electrons equally, so it has no permanent dipole moment.
3. When a nonpolar molecule like O_2 approaches a polar molecule like H_2O, the electric field from the polar molecule can distort the electron cloud of the nonpolar molecule, creating an induced dipole.
4. Specifically, the positive (hydrogen) end of H_2O attracts the electron cloud of the nearby O_2 molecule, causing the electrons in O_2 to shift slightly toward the hydrogen end, making that end of O_2 slightly negatively charged.
5. This induced dipole interaction is a type of intermolecular force that does not involve covalent bond formation but results in a weak attraction between the molecules.