Number of lone pairs on the central atom=Number of hybrid orbitals of the central atom−Number of sigma bonds of the central atom.
Number of hybrid orbitals or
Hybridisation for a molecule is given by =21(V+H−C+A)
Where V= Number of valance electrons in central atom.
H = Number of surrounding monovalent atoms.
C= Cationic charge
A = Anionic charge.
XeF6:
Number of hybrid orbitals are 7.
Number of sigma bonds formed by the central atom are 6
Number of lone pairs on the central atom=7-6=1 lone pair
XeOF4:28+4=6
Number of hybrid orbitals are 6
Number of sigma bonds formed by the central atom are 5
Number of lone pairs on the central atom=6−5=1
XeO3:
Number of hybrid orbitals=4
Number of sigma bonds formed by the central atom are 3
Number of lone pairs on the central atom=4−3=1
Hence, the total number of lone pairs on the central atom of XeO3,XeOF4andXeF6 are 3.
