Why in terms of intermolecular forces in both compounds, why ammonia has a higher boiling temp than PH3?????
Unlike PH3, NH3 can participate in hydrogen-bonding. This type of intermolecular force occurs when a hydrogen atom is attached to an electronegative atom (specifically, O, N, or F). In turn, this hydrogen atom can form an inter-molecular bond with another electronegative atom (O, N, or F) from another molecule. In this case, the P atom in PH3 is not electronegative, while the N is relatively more electronegative. As such, the NH3 can participate in hydrogen-bonding, which is a very strong type of inter-molecular force. Consequently, this raises the boiling temperature of NH3, as the h-bonding is relatively hard to break apart. Hope this helped.
