Which is the strongest type of intermolecular force present in H_2 (hydrogen gas)?

• A. Hydrogen bonding
• B. Dipole-dipole interactions
• C. Ion-dipole interactions
• D. London dispersion forces

Answer: (D)

Verified step by step guidance

1. Identify the molecular structure and polarity of H_2 (hydrogen gas). Since H_2 consists of two identical hydrogen atoms sharing electrons equally, it is a nonpolar molecule.
2. Recall that hydrogen bonding occurs only when hydrogen is directly bonded to highly electronegative atoms like nitrogen, oxygen, or fluorine. Since H_2 does not have such bonds, hydrogen bonding is not possible.
3. Dipole-dipole interactions require polar molecules with permanent dipoles. Because H_2 is nonpolar, it does not exhibit dipole-dipole interactions.
4. Ion-dipole interactions occur between ions and polar molecules. Since H_2 is a neutral, nonpolar molecule and not an ion, ion-dipole interactions are not relevant here.
5. Recognize that the only intermolecular forces present in nonpolar molecules like H_2 are London dispersion forces, which arise from temporary fluctuations in electron distribution creating instantaneous dipoles.