Chapter 20, Problem 11Q

(a)

Interpretation Introduction

Interpretation: The error in the given statements concerning each complex ion and the $\text{d}$ orbital splitting diagrams is to be predicted.

Concept introduction: Weak field ligand that has small crystal field splitting energy gives high spin due to presence of maximum unpaired electrons in lower energy ${\text{t}}_{\text{2g}}$ orbitals and higher energy orbitals.

Strong field ligand that has large crystal field splitting energy gives low spin due to presence of maximum paired electrons in lower energy ${\text{t}}_{\text{2g}}$ orbitals.

To determine: The error in the given statement “ ${\text{CoCl}}_{\text{4}}{}^{2-}$ is an example of a strong-field case having two unpaired electrons.”

(b)

Interpretation Introduction

Interpretation: The error in the given statements concerning each complex ion and the $\text{d}$ orbital splitting diagrams is to be predicted.

Concept introduction: Weak field ligand that has small crystal field splitting energy gives high spin due to presence of maximum unpaired electrons in lower energy ${\text{t}}_{\text{2g}}$ orbitals and higher energy orbitals.

Strong field ligand that has large crystal field splitting energy gives low spin due to presence of maximum paired electrons in lower energy ${\text{t}}_{\text{2g}}$ orbitals.

To determine: The error in the given statement “Because ${\text{CN}}^{-}$ is a weak-field ligand, $\text{Co}{\left(\text{CN}\right)}_{\text{6}}{}^{3-}$ will be a low-spin case having four unpaired electrons.”