Which of the following best explains why the boiling point of H_2O is higher than that of Cl_2?

• A. Cl_2 has a higher molecular mass, so it should have a higher boiling point than H_2O.
• B. H_2O molecules form hydrogen bonds, which are stronger than the dispersion forces present in Cl_2.
• C. H_2O molecules are nonpolar, while Cl_2 molecules are polar, leading to stronger intermolecular forces in H_2O.
• D. Both H_2O and Cl_2 have only London dispersion forces, so their boiling points are similar.

Answer: (B)

Verified step by step guidance

1. Identify the types of intermolecular forces present in each substance: H_2O and Cl_2.
2. Recall that H_2O is a polar molecule capable of hydrogen bonding due to the presence of O-H bonds, which are highly polar and allow strong intermolecular attractions.
3. Recognize that Cl_2 is a nonpolar molecule and only exhibits London dispersion forces, which are generally weaker than hydrogen bonds.
4. Understand that boiling point is influenced by the strength of intermolecular forces: stronger forces require more energy (higher temperature) to overcome.
5. Conclude that the higher boiling point of H_2O compared to Cl_2 is due to hydrogen bonding in H_2O being stronger than the dispersion forces in Cl_2.