Question

predict the shape of the molecules using VSEPR model Bcl3,sicl4​

Answer 1

Valence shell electron pair repulsion (VSEPR)theory :

It is a model used to predict the 3D geometry of individual molecules from the number of electron pairs surrounding their central atoms. It was developed by Gillespie & Nyholm.The various geometries are as follows according to number of lone pair present:

BeCl2:

The central atom has no lone pair and there are two bond pairs. i.e., BeCl2 is of the type EX2. Hence, it has a linear shape.

BCl3:

The central atom has no lone pair and there are three bond pairs. Hence, it is of the type EX3. Hence, it is trigonal planar.

SiCl4:

The central atom has no lone pair and there are four bond pairs. Hence, the shape of SiCl4 is tetrahedral being the EX4 type molecule.

AsF5:

The central atom has no lone pair and there are five bond pairs. Hence, AsF5 is of the type EX5. Therefore, the shape is trigonal bipyramidal.

H2S:

The central atom has one lone pair and there are two bond pairs. Hence, H2S is of the type AB2E. The shape is Bent.

PH3:

The central atom has one lone pair and there are three bond pairs. Hence, PH3 is of the EX5 type. Therefore, the shape is trigonal bipyramidal.