Question

Why NH 3 has high boiling point than PH 3 ?

Answer 1

NH3 has high boiling point than PH3  because NH3 has a higher EN than that of PH3.
hope this helps u!!!!!!!!!!!

Answer 2

when H forms bond with F,O,N then they forms hydrogen bonding in there molecule 
i.e.  H2NH--------HN2H      (two molecule of NH3 forms hydrogen bonding)
hence in NH3 & PH3 due to hydrogen bonding in NH3 , NH3 has high boiling point.