Chapter 20.3, Problem 30LC

(a)

Interpretation Introduction

Interpretation: The balanced ionic equation for the reaction is to be calculated.

Concept Introduction: A chemical process in which electrons are moved between two reactants is referred to as a redox reaction. The redox reactions include combination reactions, combustion reactions, decomposition reactions, and single-replacement reactions.

Answer to Problem 30LC

The balanced ionic equation for the reaction is as follows:

  $\text{6Zn}\left(s\right)+{\text{As}}_{\text{2}}{\text{O}}_{\text{3}}\left(aq\right)+12{\text{H}}^{+} \to 2{\text{AsH}}_{\text{3}}\left(aq\right)+6{\text{Zn}}^{\text{2+}}\left(aq\right)+3{\text{H}}_{\text{2}}\text{O}$

Explanation of Solution

An equation illustrating just the reduction or just oxidation that occurs in a redox reaction is called a half-reaction.

The oxidation and reduction half-reactions are written individually in the half-reaction approach before being compared to create a balanced redox equation.

The given reaction is as follows:

  $\text{Zn}\left(s\right)+{\text{As}}_{\text{2}}{\text{O}}_{\text{3}}\left(aq\right) \to {\text{AsH}}_{\text{3}}\left(aq\right)+{\text{Zn}}^{\text{2+}}\left(aq\right)$

First oxidation half-reaction and reduction half-reaction is to be written.

  $\stackrel{0}{Zn}(s)\to {\stackrel{+2}{Zn}}^{2+}(aq)$

  $\stackrel{+3}{{\text{As}}_{\text{2}}}{\text{O}}_{\text{3}}\left(aq\right)\to \stackrel{-3}{\text{As}}{\text{H}}_{\text{3}}\left(aq\right)$

The atoms in the half-reactions have to be balanced.

The charge is to be balanced.

The balanced ionic equation is as follows:

  $\text{6Zn}\left(s\right)+{\text{As}}_{\text{2}}{\text{O}}_{\text{3}}\left(aq\right)+12{\text{H}}^{+} \to 2{\text{AsH}}_{\text{3}}\left(aq\right)+6{\text{Zn}}^{\text{2+}}\left(aq\right)+3{\text{H}}_{\text{2}}\text{O}$

(b)

Interpretation Introduction

Interpretation: The balanced ionic equation for the reaction is to be calculated.

Concept Introduction: A chemical process in which electrons are moved between two reactants is referred to as a redox reaction. The redox reactions include combination reactions, combustion reactions, decomposition reactions, and single-replacement reactions.

Answer to Problem 30LC

The balanced ionic equation for the reaction is as follows:

  ${\text{2NiO}}_{\text{2}}\left(s\right)+{\text{S}}_{\text{2}}{\text{O}}_3^{2-}\left(aq\right) +2{\text{OH}}^{-}\to 2\text{Ni}{\left(\text{OH}\right)}_2\left(s\right)+2{\text{SO}}_3^{2-}\left(aq\right)$

Explanation of Solution

An equation illustrating just the reduction or just oxidation that occurs in a redox reaction is called a half-reaction.

The oxidation and reduction half-reactions are written individually in the half-reaction approach before being compared to create a balanced redox equation.

The given reaction is as follows:

  ${\text{NiO}}_{\text{2}}\left(s\right)+{\text{S}}_{\text{2}}{\text{O}}_3^{2-}\left(aq\right) \to \text{Ni}{\left(\text{OH}\right)}_2\left(s\right)+{\text{SO}}_3^{2-}\left(aq\right)$

First oxidation half-reaction and reduction half-reaction is to be written.

  $\begin{array}{l}\stackrel{+4}{\text{Ni}}{\text{O}}_2(s)\to \stackrel{+2}{\text{Ni}}{\left(\text{OH}\right)}_{\text{2}}(aq)\\ \stackrel{+2}{S_2}{O}_3^{2-}\left(aq\right)\to \stackrel{+4}{\text{S}}{\text{O}}_3^{2-}\left(aq\right)\end{array}$

The atoms in the half-reactions have to be balanced.

The charge is to be balanced.

The balanced ionic equation is as follows:

  ${\text{2NiO}}_{\text{2}}\left(s\right)+{\text{S}}_{\text{2}}{\text{O}}_3^{2-}\left(aq\right) +2{\text{OH}}^{-}\to 2\text{Ni}{\left(\text{OH}\right)}_2\left(s\right)+2{\text{SO}}_3^{2-}\left(aq\right)$