Which of the following molecules could participate in hydrogen bonding interactions with water?

• A. C2H6
• B. NH3
• C. CO2
• D. CH4

Answer: (B)

Verified step by step guidance

1. Understand what hydrogen bonding is: it is a special type of dipole-dipole interaction that occurs when a hydrogen atom is covalently bonded to a highly electronegative atom such as nitrogen (N), oxygen (O), or fluorine (F), and this hydrogen can interact with lone pairs on electronegative atoms in nearby molecules.
2. Examine each molecule to see if it contains hydrogen atoms bonded to N, O, or F, or if it has lone pairs on N, O, or F that can interact with water's hydrogen atoms.
3. For C2H6 (ethane), note that it contains only carbon and hydrogen atoms, with no highly electronegative atoms bonded to hydrogen, so it cannot form hydrogen bonds with water.
4. For NH3 (ammonia), observe that nitrogen is bonded to hydrogen atoms and has a lone pair, making it capable of both donating and accepting hydrogen bonds with water molecules.
5. For CO2 and CH4, recognize that CO2 is a linear molecule with no hydrogen atoms, and CH4 has hydrogen atoms bonded to carbon, which is not electronegative enough to participate in hydrogen bonding; thus, neither can form hydrogen bonds with water.