Chapter 9, Problem 9.7E

(a)

Interpretation Introduction

Interpretation:

The orbital energy level diagrams for ${\left[\text{Mn}{\left(\text{CN}\right)}_{\text{6}}\right]}^{\text{4-}}$ and ${\left[\text{Mn}{\left(\text{Cl}\right)}_{\text{6}}\right]}^{\text{4-}}$ has to be given.

Concept Introduction:

Splitting of d-orbitals in an octahedral complex:

In an octahedral complex, there are six ligands attached to the central transition metal.  The d-orbital splits into two different levels.  The bottom three energy levels are ${\text{d}}_{\text{xy}}\text{,}{\text{d}}_{\text{xz}}\text{,}{\text{d}}_{\text{yz}}$ named as ${\text{t}}_{\text{2g}}$ and the two upper levels are ${\text{d}}_{{\text{x}}^{\text{2}}{\text{-y}}^{\text{2}}}\text{\&}{\text{d}}_{{\text{z}}^{\text{2}}}$ named as ${\text{e}}_{\text{g}}$ set.

(b)

Interpretation Introduction

Interpretation:

The number of unpaired electrons in the complexes ${\left[\text{Mn}{\left(\text{CN}\right)}_{\text{6}}\right]}^{\text{4-}}$ and ${\left[\text{Mn}{\left(\text{Cl}\right)}_{\text{6}}\right]}^{\text{4-}}$ has to be given.

(c)

Interpretation Introduction

Interpretation:

The complex that absorbs longer wavelength has to be identified.

Concept Introduction:

Relation between energy and the wavelength:

The energy of a wave is directly proportional to its frequency, but inversely proportional to its wavelength.  In other words greater the energy larger will be the frequency and the shorter will be the wavelength.

  $\text{Energy}\text{α}\frac{\text{1}}{\text{wavelength}}$