Where does the lone pair comes from while drawing the flower stucture of NH3? Why does the one of the two electron does not move in the d-orbital in the exited state of NH3? Can you please explain it with the structures.

Asked by debjyotisaha98 | 12th Sep, 2014, 03:09: PM

Expert Answer:

Diagrammatic Representation:




                                                                                  Ammonia molecule

Orbital Overlap:

  • Out of the four sp3 hybrid orbitals, one contains a lone pair of electrons and other three are half filled.
  • The three half-filled sp3 hybrid orbitals of N atom overlap axially with half-filled 1s orbitals of three hydrogen atoms to form three N- h (sp3-s) sigma covalent bonds.
  • In NH3 molecule, there are three bonding pairs of electrons and one lone pair (non-bonding pair) of electrons.
  • The forces of repulsion between lone pair and bond pair of electrons decrease in the following order:
  • Lone pair-Bond pair > Bond pair- Bond pair
  • Due to this, bonding pair of electrons are pushed together and hence H-N-H bond angle is reduced from 109028’ to 107018’.

       Nitrogen does not have vacant d-orbitals.

Answered by Arvind Diwale | 14th Sep, 2014, 04:50: PM