Question

The molecular shapes of `SF_(4),CF_(4) " and " XeF_(4)` are :
A. The same, with 2, 0 and 1 lone pair of electrons respectively
B. The same, with 1,1 and 1 lone pairs of electrons respectively
C. Different, with 0,1 and 2 lone pairs of electrons respectively
D. Different with 1,0 and 2 lone pairs of electrons respectively.

Answer 1

Correct Answer - D
The structure of species can be predicted on the basis of hybridization which is turn can be known by knowing the number of hybrid orbitals (H) in that species
`H=1/2[["No. of electrons in Valence shell (H) " " No. of monovalent atoms (X)],[" "+Charge on anion (A) -Charge on cation(C)"]]`
For `SF_(4)` : No. of 5 hybrid orbitals in the central atom indicates `sp^(3)d` hybridisation. thus `SF_(4)` has 5 hybrid orbitals of which only four are consumed by F, leaving one lone pair of electrons on sulphur (valence electron)
For `CF_(4): H=1/2[4+4+0-0]=4 :. sp^(2)` hybridization
since all the four valence electrons.
For `XeF_(4) : H=1/2 (8+4+0-0) =6 :. sp^(3)d^(2)` , four form bond with F, leaving behind