Why `N(SiH_3)_3` is a weaker base than `N(CH_3)_3`?

Give reasons why the aromatic amines are weaker bases than aliphatic amines.

Explain why NH_3 is more polar than NF_3

PH_3 has lower boiling point than NH_3 . Why?

Give reasons of the following: (CH_3)_3 C-O-CH_3 on reaction with HI give (CH_3)_3 C-I and CH_3OH as the main products and not (CH_3)_3 C-OH & CH_3-I .

Arrange the following carbocation in ascending order of their stabilities (CH_3)_3 overset(oplus)C,overset(oplus)(CH_3),CH_2overset(oplus)CH_2,(CH_3)_2 overset(oplus)CH