Intermolecular forces drive deviations from ideal gas behavior

Steps:

• Ideal gases assume no intermolecular attractions or molecular volume; real gases deviate more with stronger forces or larger sizes at room temperature (25°C, 1 atm).
• Assess polarity and forces: nonpolar monatomic or small diatomic gases behave ideally; polar gases with hydrogen bonding deviate significantly.
• Compare boiling points as proxy for forces: H₂ (-253°C), Ne (-246°C), CO₂ (-78°C sublimes), NH₃ (-33°C) indicates NH₃ has strongest attractions.
• Thus, NH₃ shows largest deviation due to hydrogen bonding.

Why D is correct:

• NH₃ is highly polar with N-H bonds enabling hydrogen bonding, violating ideal gas assumption of negligible attractions (van der Waals equation shows high 'a' constant for NH₃).

Why the others are wrong:

• A. CO₂: nonpolar linear molecule with weak quadrupole interactions, minor deviations.
• B. H₂: small nonpolar diatomic with negligible forces and volume, closest to ideal.
• C. Ne: monatomic noble gas with no intermolecular forces, behaves ideally.

Final answer: D