Which of the following gases deviates most from ideal behavior under standard conditions?

• A. N_2
• B. He
• C. O_2
• D. NH_3

Answer: (D)

Verified step by step guidance

1. Understand that ideal gas behavior assumes no intermolecular forces and that gas particles occupy no volume. Deviations occur when these assumptions fail, especially under conditions of high pressure or low temperature.
2. Recall that gases with stronger intermolecular forces (like hydrogen bonding or dipole-dipole interactions) deviate more from ideal behavior because these forces cause the gas particles to attract each other, reducing pressure compared to an ideal gas.
3. Analyze the given gases: N_2, He, O_2, and NH_3. Note that N_2, He, and O_2 are nonpolar or very weakly interacting gases, while NH_3 (ammonia) is a polar molecule capable of hydrogen bonding.
4. Recognize that NH_3's hydrogen bonding leads to stronger intermolecular attractions, causing it to deviate more from ideal gas behavior under standard conditions compared to the other gases listed.
5. Conclude that among the options, NH_3 deviates most from ideal gas behavior due to its significant intermolecular forces, which is why it is the correct answer.