Chapter 17.3, Problem 17.6P

(a)

Interpretation Introduction

Interpretation:

Balanced equation for reaction below by ion-electron method has to be determined.

  ${\text{I}}^{-}+{\text{NO}}_2^{-}\to {\text{I}}_{\text{2}}+\text{NO}$

Concept Introduction:

Ion-electron method to balance redox reactions.

1. Two half-reactions with elements that got oxidized and reduced.

2. Elements other than oxygen and hydrogen should be balanced.

3. Conditions to balance $\text{O}$ and $\text{H}$ are as follows:

In acidic solution, ${\text{H}}^{+}$ and ${\text{H}}_2\text{O}$ should be used to balance $\text{O}$ and $\text{H}$.

In basic solution, equal ${\text{OH}}^{-}$ ions to ${\text{H}}^{+}$ ions should be added on both sides of balanced reaction in acidic medium.

4. For acidic medium, charge is balanced by addition of ${\text{H}}^{+}$ ion. Then combine ${\text{H}}^{+}$ and ${\text{OH}}^{-}$ to form ${\text{H}}_2\text{O}$ and cancel common ${\text{H}}_2\text{O}$ in reaction.

5. Electrons should be added to balance electric charge.

6. Finally, two half-reactions should be added and any common substance including electrons must be cancelled.

(b)

Interpretation Introduction

Interpretation:

Balanced equation for reaction below by ion-electron method has to be determined.

  ${\text{Cl}}_2+{\text{IO}}_3^{-}\to {\text{IO}}_4^{-}+{\text{Cl}}^{-}$

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

Balanced equation for reaction below by ion-electron method has to be determined.

  ${\text{AuCl}}_4^{-}+{\text{Sn}}^{2+}\to {\text{Sn}}^{4+}+\text{AuCl}+{\text{Cl}}^{-}$

Concept Introduction:

Refer to part (a).