Question

Why does NH3 have a much higher boiling point than PH3?

Answer 1

it depends on Nitrogen and phosphorus!!!!

Answer 2

Although PH3 is a larger molecule with greater dispersion forces than ammonia,NH3 has very strong and polar N-H bonds leading to strong hydrogen bonding. This dominates the intermolecular force and results in a greater attraction between NH3 than the PH3 molecules.