Chapter 19, Problem 19.47QE

(a)

Interpretation Introduction

Interpretation:

The number of unpaired electrons expected in ${{\text{[CrCl}}_{\text{6}}\text{]}}^{\text{3}-}$ octahedral complex has to be given.

Explanation of Solution

Ground state electronic configuration of $\text{Cr}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{1}}{\text{ 3d}}^{\text{5}}$.

Ground state electronic configuration of ${\text{Cr}}^{3+}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{0}}{\text{ 3d}}^3$.

The energy level diagram of ${{\text{[CrCl}}_{\text{6}}\text{]}}^{\text{3}-}$ octahedral complex is,

From the above diagram, the number of unpaired electrons expected in ${{\text{[CrCl}}_{\text{6}}\text{]}}^{\text{3}-}$ octahedral complex is 3 unpaired electrons.

(b)

Interpretation Introduction

Interpretation:

The number of unpaired electrons expected in ${{\text{[Co(CN)}}_{\text{5}}{\text{(H}}_{\text{2}}\text{O)]}}^{\text{2-}}$ octahedral complex has to be given.

Explanation of Solution

Ground state electronic configuration of $\text{Co}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{2}}{\text{ 3d}}^{\text{7}}$.

Ground state electronic configuration of ${\text{Co}}^{3+}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^0{\text{ 3d}}^6$.

The energy level diagram of ${{\text{[Co(CN)}}_{\text{5}}{\text{(H}}_{\text{2}}\text{O)]}}^{\text{2-}}$ octahedral complex is,

From the above diagram, the number of unpaired electrons expected in ${{\text{[Co(CN)}}_{\text{5}}{\text{(H}}_{\text{2}}\text{O)]}}^{\text{2-}}$ octahedral complex is 0 unpaired electrons.

(c)

Interpretation Introduction

Interpretation:

The number of unpaired electrons expected in ${{\text{[Mn(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{2}+}$ octahedral complex has to be given.

Explanation of Solution

Ground state electronic configuration of $\text{Mn}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{2}}{\text{ 3d}}^{\text{5}}$.

Ground state electronic configuration of ${\text{Mn}}^{2+}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^0{\text{ 3d}}^{\text{5}}$.

The energy level diagram of ${{\text{[Mn(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{2}+}$ octahedral complex is,

From the above diagram, the number of unpaired electrons expected in ${{\text{[Mn(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{2}+}$ octahedral complex is 5 unpaired electrons.

(d)

Interpretation Introduction

Interpretation:

The number of unpaired electrons expected in ${{\text{[Rh(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex has to be given.

Explanation of Solution

Ground state electronic configuration of $\text{Rh}$ is,

  ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{2}}{\text{ 3d}}^{\text{10}}{\text{ 4p}}^{\text{6}}{\text{ 5s}}^{\text{1}}{\text{ 4d}}^{\text{8}}$.

Ground state electronic configuration of ${\text{Rh}}^{3+}$ is,

  ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{2}}{\text{ 3d}}^{\text{10}}{\text{ 4p}}^{\text{6}}{\text{ 5s}}^0{\text{ 4d}}^6$.

The energy level diagram of ${{\text{[Rh(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex is,

From the above diagram, the number of unpaired electrons expected in ${{\text{[Rh(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex is 0 unpaired electrons.

(e)

Interpretation Introduction

Interpretation:

The number of unpaired electrons expected in ${{\text{[V(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex has to be given.

Explanation of Solution

Ground state electronic configuration of $\text{V}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^{\text{2}}{\text{ 3d}}^{\text{3}}$.

Ground state electronic configuration of ${\text{V}}^{3+}$ is ${\text{1s}}^{\text{2}}{\text{ 2s}}^{\text{2}}{\text{ 2p}}^{\text{6}}{\text{ 3s}}^{\text{2}}{\text{ 3p}}^{\text{6}}{\text{ 4s}}^0{\text{ 3d}}^2$.

The energy level diagram of ${{\text{[V(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex is,

From the above diagram, the number of unpaired electrons expected in ${{\text{[V(H}}_{\text{2}}{\text{O)}}_{\text{6}}\text{]}}^{\text{3}+}$ octahedral complex is 2 unpaired electrons.