Question

20. Which among the following has the maximum value of dipole moment ? (A) \( SO _{3} \) (B) \( NF _{3} \) (C) \( NH _{3} \) (D) \( N \left( SiH _{3}\right)^{3} \)

Answer 1

(A) SO₃ :

(B) NF₃ :

(C) NH₃ :

(D) N(SiH₃)³ :

Due to delocalization of lone pair of Nitrogen with vacant d-orbital of Si.Cause, the molecule become planer. that's why \(\mu= 0\).

NH₃ has maximum dipole moment. NF₃ and NH₃ both molecule have Pyramidal shape with lone pair of electron on nitrogen atom.There is a greater electronegative difference on nitrogen atom.

There is a greater electronegative difference between N and H atom than N and F atom. In NH₃, the orbital dipole due to lone pair is in the same direction. while in the opposite directions. that's why. NH₃ has more dipole moment than NF₃.