Chapter 16, Problem 86A

(a)

Interpretation Introduction

Interpretation: The number of moles of ions present in $0.10\text{mol}$ of ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$ is to be calculated.

Concept Introduction: Ions are charged chemical compounds formed by the loss or acceptance of electrons. The one which loses electrons is cations while the one that gets electrons are anions.

Answer to Problem 86A

The total number of moles of ions in $0.10\text{mol}$

  ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$ is $0.3\text{mol}$ .

Explanation of Solution

The dissociation of ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}$ leads to the formation of potassium and sulfate ions as,

  ${\text{K}}_{\text{2}}{\text{SO}}_{\text{4}}\to 2{\text{K+SO}}_{\text{4}}{}^{2-}$

So, two moles of potassium and one mole of sulfate ions are produced.

The total number of moles of ions is:

  $2\times 0.1+0.1=0.3\text{mol}$

So, the total number of moles of ions is $0.3\text{mol}$ .

(b)

Interpretation Introduction

Interpretation: The number of moles of ions present in $0.10\text{mol}$ of ${\left({\text{FeNO}}_3\right)}_2$ is to be calculated.

Concept Introduction: Ions are charged chemical compounds formed by the loss or acceptance of electrons. The one which loses electrons is cations while the one that gets electrons are anions.

Answer to Problem 86A

The total number of moles of ions in $0.10\text{mol}$

  ${\left({\text{FeNO}}_3\right)}_2$ is $0.4\text{mol}$ .

Explanation of Solution

The dissociation of ${\left({\text{FeNO}}_3\right)}_2$ results in the formation of ions,

  ${\left({\text{FeNO}}_3\right)}_2\to {\text{Fe}}^{3+}{\text{+3NO}}_3{}^{-}$

So, three moles of nitrate and one mole of ferrous ions are produced.

The total number of moles of ions is:

  $3\times 0.1+0.1=0.4\text{mol}$

So, the total number of moles of ions is $0.4\text{mol}$ .

(c)

Interpretation Introduction

Interpretation: The number of moles of ions present in $0.10\text{mol}$ of ${\left({\text{Al}}_2{\text{SO}}_4\right)}_3$ is to be calculated.

Concept Introduction: Ions are charged chemical compounds formed by the loss or acceptance of electrons. The one which loses electrons is cations while the one that gets electrons are anions.

Answer to Problem 86A

The total number of moles of ions in $0.10\text{mol}$

  ${\left({\text{Al}}_2{\text{SO}}_4\right)}_3$ is $0.5\text{mol}$ .

Explanation of Solution

The dissociation of ${\left({\text{Al}}_2{\text{SO}}_4\right)}_3$ results in the formation of ions,

  ${\left({\text{Al}}_2{\text{SO}}_4\right)}_3\to 2{\text{Al}}^{3+}{\text{+3SO}}_4{}^{2-}$

So, two aluminum and three sulfate ions are produced.

The total number of moles of ions is,

  $2\times 0.1+3\times 0.1=0.5\text{mol}$

So, the total number of moles of ions is $0.5\text{mol}$ .

(d)

Interpretation Introduction

Interpretation: The number of moles of ions present in $0.10\text{mol}$ of $\left({\text{NiSO}}_4\right)$ is to be calculated.

Concept Introduction: Ions are charged chemical compounds formed by the loss or acceptance of electrons. The one which loses electrons is cations while the one that gets electrons are anions.

Answer to Problem 86A

The total number of moles of ions in $0.10\text{mol}$

  $\left({\text{NiSO}}_4\right)$ is $0.2\text{mol}$ .

Explanation of Solution

The dissociation of $\left({\text{NiSO}}_4\right)$ results in the formation of ions,

  $\left({\text{NiSO}}_4\right)\to {\text{Ni}}^{2+}{\text{+SO}}_4{}^{2-}$

The total number of moles of ions is,

  $0.1+0.1=0.2\text{mol}$

So, the total number of moles of ions is $0.2\text{mol}$ .