Chapter 19, Problem 32QAP

Interpretation Introduction

(a)

Interpretation:

The electronic configuration for metal ion ${\text{Cd}}^{2+}$ needs to be determined.

Concept introduction:

The simplest method for describing the arrangement of electrons in an atom is by writing its electronic configuration. Since the set of four quantum numbers is used to describe the atomic orbitals in an atom, therefore by writing the electronic configuration one can get details of the number of electrons present in each sublevel. When the electronic configuration of an atom is written, it describes the number of electron present in each sublevel by the superscript. While writing the electronic configuration, it is assumed that atom is present in its isolated gaseous state. Electrons are filled in order of the increasing energies of the various sublevels.

Atomic number of an element gives the total number of electrons present in an atom. In case of transition metal cations, the electrons that are present beyond the noble gas are located in their inner d- orbitals (3d orbitals in case of 3d transition metal elements), this means that they have no outer s- electrons and the distribution of electrons is according to Hund’s rule which states that when orbitals of equal energy are available, then electrons enter singly in the respective orbitals, this gives rise to maximum number of unpaired electrons in transition metal cations.

Answer to Problem 32QAP

The electronic configuration for Cd²+ is ${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^{\text{10}}{\text{4s}}^{\text{2}}{\text{4p}}^{\text{6}}{\text{4d}}^{\text{10}}$.

Explanation of Solution

Cadmium is a 4d transition metal element and its atomic number is 48. Its electronic configuration can be written as follows:

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

When it two electrons this leads to the formation of Cd²+ cation, and its electronic configuration becomes:

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

This filling of electrons in the atomic orbitals takes place according to the Aufbau principal which states that when an atom is present in its ground state, electrons are filled in order of increasing energy of the orbitals, which means that firstly lower energy orbitals are filled, and then filling of higher energy orbitals takes place.

Interpretation Introduction

(b)

Interpretation:

The electronic configuration for metal ion ${\text{Fe}}^{2+}$ needs to be determined.

Concept introduction:

The simplest method for describing the arrangement of electrons in an atom is by writing its electronic configuration. Since the set of four quantum numbers is used to describe the atomic orbitals in an atom, therefore by writing the electronic configuration one can get details of the number of electrons present in each sublevel.When the electronic configuration of an atom is written, it describes the number of electron present in each sublevel by the superscript. While writing the electronic configuration, it is assumed that atom is present in its isolated gaseous state. Electrons are filled in order of the increasing energies of the various sublevels.

Atomic number of an element gives the total number of electrons present in an atom. In case of transition metal cations, the electrons that are present beyond the noble gas are located in their inner d- orbitals (3d orbitals in case of 3d transition metal elements), this means that they have no outer s- electrons and the distribution of electrons is according to Hund’s rule which states that when orbitals of equal energy are available, then electrons enter singly in the respective orbitals, this gives rise to maximum number of unpaired electrons in transition metal cations.

Answer to Problem 32QAP

The electronic configuration for Fe²+ is ${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^6$.

Explanation of Solution

Iron is a 3d transition metal element and its atomic number is 26. Its electronic configuration can be written as follows:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^6{\text{4s}}^2$

When it two electrons this leads to the formation of Fe²+ cation, and its electronic configuration becomes:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^6$

This filling of electrons in the atomic orbitals takes place according to the Aufbau principal. It states that when an atom is present in its ground state, electrons are filled in order of increasing energy of the orbitals, which means that firstly, lower energy orbitals are filled, and then filling of higher energy orbitals takes place.

Interpretation Introduction

(c)

Interpretation:

The electronic configuration for metal ion ${\text{Pt}}^{2+}$ needs to be determined.

Concept introduction:

The simplest method for describing the arrangement of electrons in an atom is by writing its electronic configuration. Since the set of four quantum numbers is used to describe the atomic orbitals in an atom, therefore by writing the electronic configuration, one can get details of the number of electrons present in each sublevel. When the electronic configuration of an atom is written, it describes the number of electron present in each sublevel by the superscript. While writing the electronic configuration, it is assumed that atom is present in its isolated gaseous state. Electrons are filled in order of the increasing energies of the various sublevels.

Atomic number of an element gives the total number of electrons present in an atom. In case of transition metal cations, the electrons that are present beyond the noble gas are located in their inner d- orbitals (3d orbitals in case of 3d transition metal elements), this means that they have no outer s- electrons and the distribution of electrons is according to Hund’s rule which states that, when orbitals of equal energy are available, then electrons enter singly in the respective orbitals, this gives rise to maximum number of unpaired electrons in transition metal cations.

Answer to Problem 32QAP

Theelectronic configuration for Pt²+ is ${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^{\text{10}}{\text{4s}}^{\text{2}}{\text{4p}}^{\text{6}}{\text{4d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{6}}{\text{4f}}^{\text{14}}{\text{5d}}^8$.

Explanation of Solution

Platinum is a 5d transition metal element and its atomic number is 78. Its electronic configuration can be written as follows:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^{\text{10}}{\text{4s}}^{\text{2}}{\text{4p}}^{\text{6}}{\text{4d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{6}}{\text{4f}}^{\text{14}}{\text{5d}}^{\text{9}}{\text{6s}}^{\text{1}}$

When it two electrons this leads to the formation of Pt²+ cation, and its electronic configuration becomes:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^{\text{10}}{\text{4s}}^{\text{2}}{\text{4p}}^{\text{6}}{\text{4d}}^{\text{10}}{\text{5s}}^{\text{2}}{\text{5p}}^{\text{6}}{\text{4f}}^{\text{14}}{\text{5d}}^8$

This filling of electrons in the atomic orbitals takes place according to the Aufbau principal. It states that, when an atom is present in its ground state, electrons are filled in order of increasing energy of the orbitals, which means that firstly lower energy orbitals are filled, and then filling of higher energy orbitals takes place.

Interpretation Introduction

(d)

Interpretation:

The electronic configuration for metal ion ${\text{Mn}}^{2+}$ needs to be determined.

Concept introduction:

The simplest method for describing the arrangement of electrons in an atom is by writing its electronic configuration. Since the set of four quantum numbers is used to describe the atomic orbitals in an atom, therefore by writing the electronic configuration one can get details of the number of electrons present in each sublevel. When the electronic configuration of an atom is written, it describes the number of electron present in each sublevel by the superscript. While writing the electronic configuration, it is assumed that atom is present in its isolated gaseous state. Electrons are filled in order of the increasing energies of the various sublevels.

Atomic number of an element gives the total number of electrons present in an atom. In case of transition metal cations, the electrons that are present beyond the noble gas are located in their inner d- orbitals (3d orbitals in case of 3d transition metal elements), this means that they have no outer s- electrons and the distribution of electrons is according to Hund’s rule. It states that when orbitals of equal energy are available, then electrons enter singly in the respective orbitals, which gives rise to maximum number of unpaired electrons in transition metal cations.

Answer to Problem 32QAP

The electronic configuration forMn²+ is ${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^5$.

Explanation of Solution

Manganese is a 3d transition metal element and its atomic number is 25. Its electronic configuration can be written as follows:

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

When it two electrons this leads to the formation of Mn²+ cation, and its electronic configuration becomes:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^5$

This filling of electrons in the atomic orbitals takes place according to the Aufbau principal. It states that when an atom is present in its ground state, electrons are filled in order of increasing energy of the orbitals, which means that firstly, lower energy orbitals are filled, and then filling of higher energy orbitals takes place.

Interpretation Introduction

(e)

Interpretation:

The electronic configuration for metal ion ${\text{Ni}}^{3+}$ needs to be determined.

Concept introduction:

The simplest method for describing the arrangement of electrons in an atom is by writing its electronic configuration. Since the set of four quantum numbers is used to describe the atomic orbitals in an atom, therefore by writing the electronic configuration, one can get details of the number of electrons present in each sublevel. When the electronic configuration of an atom is written, it describes the number of electrons present in each sublevel by the superscript. While writing the electronic configuration, it is assumed that atom is present in its isolated gaseous state. Electrons are filled in order of the increasing energies of the various sublevels.

Atomic number of an element gives the total number of electrons present in an atom. In case of transition metal cations, the electrons that are present beyond the noble gas are located in their inner d- orbitals (3d orbitals in case of 3d transition metal elements), this means that they have no outer s- electrons and the distribution of electrons is according to Hund’s rule which states that when orbitals of equal energy are available, then electrons enter singly in the respective orbitals. This gives rise to maximum number of unpaired electrons in transition metal cations.

Answer to Problem 32QAP

The electronic configuration forNi³+ is ${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^7$.

Explanation of Solution

Nickel is a 3d transition metal element and its atomic number is 28. Its electronic configuration can be written as follows:

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

When it three electrons it leads to the formation of Ni³+ cation, and its electronic configuration becomes:

${\text{1s}}^{\text{2}}{\text{2s}}^{\text{2}}{\text{2p}}^{\text{6}}{\text{3s}}^{\text{2}}{\text{3p}}^{\text{6}}{\text{3d}}^7$

This filling of electrons in the atomic orbitals takes place according to the Aufbau principal. It states that when an atom is present in its ground state, electrons are filled in order of increasing energy of the orbitals, which means that firstly, lower energy orbitals are filled, and then filling of higher energy orbitals takes place.