Question

Discuss the shape of the following molecules using the VSEPR model: BeCl2, BCl3, SiCl4, AsF5, H2S, PH3

Answer 1

BeCl₂

The central atom has no lone pair and there are two bond pairs. i.e., BeCl₂ is of the type AB₂. 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 AB₃. 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 AB₄ type molecule. 

AsF₅: 

The central atom has no lone pair and there are five bond pairs. Hence, AsF₅ is of the type AB₅. 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 AB₃E type. Therefore, the shape is trigonal bipyramidal.