Question

which of these species can exhibit hydrogen bonding among themselves? a) h₂s b) ch₄ c) ch₃f d) n₂h₄

Explanation:

Hydrogen bonding occurs when a hydrogen atom is bonded to a highly electronegative atom (N, O, or F) in one molecule and interacts with another electronegative atom in a neighboring molecule.

• For \(H_2S\), sulfur is not as electronegative as N, O, or F (required for strong hydrogen - bonding).
• For \(CH_4\), carbon is not highly electronegative enough to cause significant hydrogen - bonding (C - H bonds do not lead to hydrogen bonding in the context of the strict definition involving N, O, F).
• For \(CH_3F\), the hydrogen is bonded to carbon, not to the highly electronegative fluorine. So, no hydrogen bonding among \(CH_3F\) molecules.
• For \(N_2H_4\), the hydrogen is bonded to nitrogen. Nitrogen is a highly electronegative atom (\(EN = 3.04\)), and \(N_2H_4\) has the structure \(H_2N - NH_2\) where the hydrogen - nitrogen bonds allow for hydrogen bonding among \(N_2H_4\) molecules.

Answer:

d) \(N_2H_4\)