Chapter 17, Problem 17.39QP

(a)

Interpretation Introduction

To determine: The chemical names of coordination compounds.

Interpretation: The chemical names of coordination compounds are to be given.

Concept introduction: The naming of the compound is done on the basis of ligands attached to it and the charge or oxidation number present on each ligand or atoms.

Answer to Problem 17.39QP

The name of $\left[\text{Zn}{\left(\text{en}\right)}_2\right]{\text{SO}}_4$ is, $\text{Ethylenediaminezinc}\left(\text{II}\right)\text{sulphate}$.

The name of $\left[\text{Ni}{\left({\text{NH}}_3\right)}_5\left({\text{H}}_2\text{O}\right)\right]{\text{Cl}}_2$ is, $\text{Pentaamineaquanickel}\left(\text{II}\right)\text{chloride}$.

The name of ${\text{K}}_4\text{Fe}{\left(\text{CN}\right)}_6$ is, $\text{Potassium}\text{hexacyanoferrate}\left(\text{II}\right)$.

Explanation of Solution

The name of given compound $\left[\text{Zn}{\left(\text{en}\right)}_2\right]{\text{SO}}_4$ is,

$\text{Ethylenediaminezinc}\left(\text{II}\right)\text{sulphate}$.

The name of given compound $\left[\text{Ni}{\left({\text{NH}}_3\right)}_5\left({\text{H}}_2\text{O}\right)\right]{\text{Cl}}_2$ is,

$\text{Pentaamineaquanickel}\left(\text{II}\right)\text{chloride}$.

The name of given compound ${\text{K}}_4\text{Fe}{\left(\text{CN}\right)}_6$ is,

$\text{Potassium}\text{hexacyanoferrate}\left(\text{II}\right)$.

(b)

Interpretation Introduction

To determine: The charge on the complex, the oxidation state of the metal ion, and the coordination number of the metal in the complex ion.

Interpretation: The charge on the complex, the oxidation state of the metal ion, and the coordination number of the metal in the complex ion is to be identified.

Concept introduction: Coordination number of complex relies upon the ligands that are attached to the central metal. Oxidation state of the metal ion is calculated by the formula,

$\text{Sum}\text{of}\text{charges}\text{of}\text{constituent}\text{atoms}=\text{overall}\text{charge}\text{of}\text{complex}$

Answer to Problem 17.39QP

The oxidation state of the zinc metal is $+2$, the charge on the complex ion is $+2$ and the coordination number of the metal is four.

The oxidation state of the nickel metal is $+2$, the charge on the complex ion is $+2$ the coordination number of the metal is six.

The oxidation state of the iron metal is $+2$, the charge on the ion is $-4$ the coordination number of the metal is six.

Explanation of Solution

The given compound is $\left[\text{Zn}{\left(\text{en}\right)}_2\right]{\text{SO}}_4$.

The charge of $\text{en}$ ligand is $0$.

The charge of sulphate ion is $-2$.

The oxidation state of zinc metal is assumed to be $x$.

The oxidation number of zinc metal is calculated by the formula,

$\text{Sum}\text{of}\text{charges}\text{of}\text{constituent}\text{atoms}=\text{overall}\text{charge}\text{of}\text{complex}$ (1)

Substitute the values of charges or oxidation number of constituent atoms in equation (1).

$\begin{array}{c}+x+0+\left(-2\right)=0\\ -2+x=0\\ x=+2\end{array}$

Therefore, the oxidation state of the zinc metal is $+2$, the charge on the complex ion is $+2$ because sulphate has $-2$ charge that is present outside the square bracket and the coordination number of the metal is four.

Similarly,

The given compound is $\left[\text{Ni}{\left({\text{NH}}_3\right)}_5\left({\text{H}}_2\text{O}\right)\right]{\text{Cl}}_2$.

The charge of amine ligand is $0$.

The charge of water molecule is $0$.

The oxidation state of chloride ion is $-1$.

The oxidation state of nickel metal is assumed to be $x$.

The oxidation number of nickel metal is calculated by the formula,

$\text{Sum}\text{of}\text{charges}\text{of}\text{constituent}\text{atoms}=\text{overall}\text{charge}\text{of}\text{complex}$ (1)

Substitute the values of charges or oxidation number of constituent atoms in equation (1).

$\begin{array}{c}+x+0+0+\left(2\times -1\right)=0\\ -2+x=0\\ x=+2\end{array}$

Therefore, the oxidation state of the nickel metal is $+2$, the charge on the complex ion is $+2$ because two chloride ions have $-2$ charge that is present outside the square bracket and the coordination number of the metal is six.

Similarly,

The given compound is ${\text{K}}_4\text{Fe}{\left(\text{CN}\right)}_6$.

The oxidation state of potassium ion is $+1$.

The oxidation state of cyanide is is $-1$.

The oxidation state of iron metal is assumed to be $x$.

The oxidation number of iron metal is calculated by the formula,

$\text{Sum}\text{of}\text{charges}\text{of}\text{constituent}\text{atoms}=\text{overall}\text{charge}\text{of}\text{complex}$ (1)

Substitute the values of charges or oxidation number of constituent atoms in equation (1).

$\begin{array}{c}4\left(+1\right)+x+\left(6\times -1\right)=0\\ +4+x-6=0\\ -2+x=0\\ x=+2\end{array}$

Therefore, the oxidation state of the iron metal is $+2$, the charge on the ion is $-4$ because four potassium ions have $+4$ charge that balance the charge of the complex and the coordination number of the metal is six.

Conclusion

1. a. The name of $\left[\text{Zn}{\left(\text{en}\right)}_2\right]{\text{SO}}_4$ is, $\text{Ethylenediaminezinc}\left(\text{II}\right)\text{sulphate}$.

   The name of $\left[\text{Ni}{\left({\text{NH}}_3\right)}_5\left({\text{H}}_2\text{O}\right)\right]{\text{Cl}}_2$ is, $\text{Pentaamineaquanickel}\left(\text{II}\right)\text{chloride}$.

   The name of ${\text{K}}_4\text{Fe}{\left(\text{CN}\right)}_6$ is, $\text{Potassium}\text{hexacyanoferrate}\left(\text{II}\right)$.

2. b. The oxidation state of the zinc metal is $+2$, the charge on the complex ion is $+2$ and the coordination number of the metal is four.

   The oxidation state of the nickel metal is $+2$, the charge on the complex ion is $+2$ the coordination number of the metal is six.

   The oxidation state of the iron metal is $+2$, the charge on the ion is $-4$ the coordination number of the metal is six.