Question

using vsepr theory predict the species which has square pyramidal shape sncl2 ccl4 so3 brf5

Answer 1

using vsepr theory predict the species which has square pyramidal shape are OSF

2

Answer 2

As per VSEPR theory, the arrangement of atoms will always be in such a manner in which the electron pair repulsion is minimum.

(i) SnCl$_{2}$

In SnCl$_{2}$ the total number of electrons surrounding the central Sn-atom is 4.

Valence electrons of Sn- atom + 2 electrons of two σ - bonded Cl atoms

= 4 + 2 = 6 electrons or 3 electron pairs

= 2 σ-bond pairs + 1 lone pair

∴ The structure of SnCl$_{2}$ is Trigonal pyramidal shaped or V-shaped due to the present of lone Pair.

(ii) CCl$_{4}$

In CCl$_{4}$ the total number of electrons surrounding the central C-atom is 4.

Valence electrons of C- atom + 4 electrons of four σ - bonded Cl atoms

= 4 + 4 = 8 electrons or 4 electron pairs

= 4 σ-bond pairs

The four bond pairs will experience minimum repulsion if they are tetrahedrally oriented.

∴ The structure of CCl$_{4}$ molecule will be Tetrahedral.

(iii) SO$_{3}$

In SO$_{3}$ the total number of electrons surrounding the central S-atom is 6.

Valence electrons of S- atom + 6 electrons of two doubly bonded O-atom

= 6 + 6 = 12 electrons or 6 electron pairs

As no lone pair exists on the central atom there is no distortion in the bond angle.

∴ The structure of Sulphur Trioxide (SO$_{3}$) is bent shaped or trigonal pyramidal or trigonal planar, where the bond angle is 120°.

(iv) BrF$_{5}$

In BrF$_{5}$ the total number of electrons surrounding the central Br-atom is 7.

Valence electrons of Br- atom + 5 electrons of five σ - bonded F atoms

= 7 + 5 = 12 electrons or 6 electron pairs

= 5 σ-bond pairs + 1 lone pair.

In order to minimise the extent of mutual repulsion, these six electron pairs will adopt octahedral geometry in which any one of the positions will be occupied by the lone pair. The lone pair will occupy axial position preferably in order to stabilize the structure.

∴ The structure of BrF$_{5}$ molecule will be Square Pyramidal.

∴ Among the given species, BrF$_{5}$ is found to have Square pyramidal structure.