Chapter 19, Problem 22E

(a)

Interpretation Introduction

Interpretation: Thename for the given coordination complex needs to be determined.

• ${\text{[Co(NH}}_{\text{3}}{\text{)}}_6{\text{]Cl}}_{\text{2}}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{[Co(NH}}_{\text{3}}{\text{)}}_6{\text{]Cl}}_{\text{2}}$ = hexaamminecobalt(II) chloride

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{[Co(NH}}_{\text{3}}{\text{)}}_6{\text{]Cl}}_{\text{2}}$ , Cl- must be counter ion so the complex ion must have +2 charge. In the complex ion, there are 6 ligands so hexa- prefix must be used with −ammine and that will be followed by name of metal ion Cobalt (II).

Hence name must be hexaamminecobalt(II) chloride.

(b)

Interpretation Introduction

Interpretation: The name for the given coordination complex needs to be determined.

• ${\text{[Co(H}}_{\text{2}}{\text{O)}}_6{\text{]I}}_{\text{3}}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{[Co(H}}_{\text{2}}{\text{O)}}_6{\text{]I}}_{\text{3}}$ = hexaaquacobalt(III) iodide

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{[Co(H}}_{\text{2}}{\text{O)}}_6{\text{]I}}_{\text{3}}$ , I-must be counter ion so the complex ion must have +3 charge. In the complex ion, there are 6 ligands so hexa- prefix must be used with name of ligand that is −aqua and the name of metal ion will come with oxidation statethat is +3.

Hence name must be hexaaquacobalt(III) iodide.

(c)

Interpretation Introduction

Interpretation: The name for the given coordination complex needs to be determined.

• ${\text{K}}_{\text{2}}{\text{[PtCl}}_4\text{]}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{K}}_{\text{2}}{\text{[PtCl}}_4\text{]}$ = potassium tetrachloroplatinate(II)

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{K}}_{\text{2}}{\text{[PtCl}}_4\text{]}$ , K+must be counter ion so the complex ion must have -1 charge. In the complex ion there are 4 ligands so tetra- prefix must be used with name of ligand that is −chloro and the name of metal ion will come with oxidation state that is +2.

Hence name must be potassium tetrachloroplatinate(II)

(d)

Interpretation Introduction

Interpretation: The name for the given coordination complex needs to be determined.

• ${\text{K}}_4{\text{[PtCl}}_6\text{]}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{K}}_4{\text{[PtCl}}_6\text{]}$ = potassium hexachloroplatinate(II)

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{K}}_{\text{2}}{\text{[PtCl}}_4\text{]}$ , K+ must be counter ion so the complex ion must have -1 charge. In the complex ion there are 4 ligands so hexa- prefix must be used with name of ligand that is −chloro and the name of metal ion will come with oxidation state that is +2.

Hence name must be potassium hexachloroplatinate(II).

(e)

Interpretation Introduction

Interpretation: The name for the given coordination complex needs to be determined.

• ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_{\text{5}}{\text{Cl]Cl}}_{\text{2}}$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_{\text{5}}{\text{Cl]Cl}}_{\text{2}}$ = pentamminchlorochromium(III) chloride

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_{\text{5}}{\text{Cl]Cl}}_{\text{2}}$ , Cl-must be counter ion so the complex ion must have -2 charge. In the complex ion there are 5ammine ligands and one chloro ligand which must be written in alphabetical manner. Since there is -2 charge on complex ion and it has -1 chloro ligand therefore the metal ion must have +3 charge.Hence name must be pentamminchlorochromium(III) chloride.

(e)

Interpretation Introduction

Interpretation: The name for the given coordination complex needs to be determined.

• ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_3{{\text{(NO}}_{\text{2}}\text{)}}_{\text{3}}\text{] }$

Concept Introduction: A coordination complex is composed of two main parts; metal atom/ ion and ligand. Ligands are the atom/ group of atom/ ion that can donate its extra pair of electrons to the electron deficient metal cation. It leads to the formation of coordinate bond between metal ion and ligand.

Answer to Problem 22E

  ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_3{{\text{(NO}}_{\text{2}}\text{)}}_{\text{3}}\text{] }$ = triamminetrinitrochromium(III)

Explanation of Solution

In the formula of writing and naming of coordination complex; IUPAC rule must be followed.

• The name of ligand will come with prefix of number of ligands.
• Name of metal will come with oxidation number in Roman numeral.
• Name of cation will come first followed by name of anion.
• The ligands are named before the metal ion in sequence of neutral, negative, positive.
• The name of anionic ligand must be ended in -ido.
• The name of complex ion with negative charge must be end in −ate.

In ${\text{[Cr(NH}}_{\text{3}}{\text{)}}_3{{\text{(NO}}_{\text{2}}\text{)}}_{\text{3}}\text{] }$ , there is no counter ion hence the complex ion must be neutral. There are two types of ligands, ammine (neutral ligand) and nitro (anionic ligand with -1 charge). Hence the balance the -3 charge of nitro ligand, the metal ion must have +3 charge on it .Hence name must be triamminetrinitrochromium(III).