Total number of lone pairs in XeOF4 is:
1
Firstly Central atom in XeOF4 is Xe [number of valence electrons in Xe is 8 which is more than in O which is 6]
Number of valance electrons in Xe is 8.
Applying VSEPR,
ep = (V+L+A−C)2 = (8+5+0−0)2 = 132
So, VSEPR theory does not hold here.
Therefore, we will apply AVSEPR theory.
So, ep = (V+L+A−C)2 = (8+4)2 = 6
[We have to ignore oxygen while calculating ep]
Now, because we have 6 ep & 5 ligands [including oxygen]
The number of lone pairs = 1