With which of the following compounds will NH_3 experience only dispersion (London) intermolecular forces?

• A. HF
• B. H_2O
• C. CH_4
• D. CO

Answer: (C)

Verified step by step guidance

1. Identify the types of intermolecular forces present in each compound listed: HF, H_2O, CH_4, and CO.
2. Recall that NH_3 (ammonia) is a polar molecule capable of hydrogen bonding due to the N-H bonds and the lone pair on nitrogen.
3. Understand that hydrogen bonding occurs when a hydrogen atom is directly bonded to highly electronegative atoms like F, O, or N, leading to strong dipole-dipole interactions.
4. Analyze each compound: HF and H_2O both have hydrogen bonding because they contain H bonded to F and O respectively; CO is a polar molecule with dipole-dipole forces; CH_4 is nonpolar and only exhibits dispersion (London) forces.
5. Conclude that NH_3 will experience only dispersion forces when interacting with CH_4, since CH_4 cannot participate in hydrogen bonding or dipole-dipole interactions.