PH3 has lower boiling point than NH3.explain.

In case of NH3 due to high electro negativity of nitrogen the molecules are bind together by intermolecular hydrogen bond which is not in case of PH3

Unlike NH3 & PH3 molecules are not associated through hydrogen bonding in liquid state. That is why boiling point of PH3 is lower than NH3.

Basically for 2 reasons - 

a) The presence of Hydrogen bonds in NH3 makes it thermostable with respect to that of PH3 ( which lacks H-bonding) so. it's easy to break the bonds of PH3 which results in low boiling point of PH3

 

b) the bond angle of PH3 is less than that of NH3. so PH3 experiences more lone pair - bond pair repulsion with respect to that of NH3 resulting in the weakening of bonds of PH3 and hence lowering the boiling point of PH3

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Give reason : F2 doesnot exbit positive oxidation state

Although PH3 is a larger molecule with greater dispersion forces than ammonia,NH3 has very polar N-H bonds leading to strong hydrogen bonding. This the dominant intermolecular force and results in a greater attraction between NH3molecules than there is between PH3 molecules

Unlike NH3 , PH3 molecules are not associated through hydrogen bonding in liquid state . Therefore boiling point of PH3 is lower than NH3.