Chapter 2, Problem 22P

Interpretation Introduction

Interpretation:

1. On steric grounds, out of cis-$\left[{\text{PtCl}}_{\text{2}}{{\text{(PPh}}_{\text{3}}\text{)}}_{\text{2}}\right]$ or trans-$\left[{\text{PtCl}}_{\text{2}}{{\text{(PPh}}_{\text{3}}\text{)}}_{\text{2}}\right]$ is favoured, is to be determined.

2. By using VSEPR model, ${\text{SNF}}_3$ is tetrahedral but ${\text{SF}}_4$ has a see-saw geometry is to be explained.

3. ${\text{KrF}}_{\text{2}}$ is a linear molecule rather than a bent molecule is to be explained.

Concept Introduction:

The VSEPR theory provides the simple model for predicting the shapes of molecular species based on minimizing the electrostatic repulsion of a molecule's valence electrons around a central atom.

Electron-electron repulsions decrease in the order:

Lone pair-lone pair > lone pair-bond pair > bond pair-bond pair

The lone pair of electrons is stereo chemically active if the presence of a lone pair of electrons influences the shape of a molecule or ion and if it has no effect, the lone pair is stereo chemically inactive.

Species that have same molecular formulae but have different constitutional formulae or different stereo chemical formulae formula are called isomers.