Chapter 18, Problem 18.26QE

(a)

Interpretation Introduction

Interpretation:    

The balanced equation for the following half reaction has to be identified and also specify whether the reaction is an oxidation or reduction reaction.

  ${\text{a) H}}_{\text{2}}{\text{O}}_{\text{2}}\text{(aq) }\to {\text{ O}}_{\text{2}}\text{(g) (in acid)}$

Concept Introduction:

Steps for balancing half –reactions in ACIDIC solution:

• Balance all atoms except H and O in half reaction.
• Balance O atoms by adding water to the side missing O atoms.
• Balance the H atoms by adding ${\text{H}}^{\text{+}}$ to the side missing H atoms.
• Balance the charge by adding electrons to side with more total positive charge.
• Make the number of electrons the same in both half reactions by multiplication, while avoiding fractional number of electrons.

Steps for balancing half –reactions in BASIC solution:

• Balance all atoms except H and O in half reaction.
• Balance O atoms by adding water to the side missing O atoms.
• Balance the H atoms by adding ${\text{H}}^{\text{+}}$ to the side missing H atoms.
• Balance the charge by adding electrons to side with more total positive charge.
• Make the number of electrons the same in both half reactions by multiplication, while avoiding fractional number of electrons.
• Add the same numbers of ${\text{OH}}^{\text{-}}$ groups as there are ${\text{H}}^{\text{+}}$ present to both sides of the equation.

(b)

Interpretation Introduction

Interpretation:    

The balanced equation for the following half reaction has to be identified and also specify whether the reaction is an oxidation or reduction reaction.

  ${\text{b) H}}_{\text{2}}{\text{C}}_{\text{2}}{\text{O}}_{\text{4}}\text{(aq) }\to {\text{ CO}}_{\text{2}}\text{(g) (in acid)}$

Concept Introduction:

Refer to (a)

(c)

Interpretation Introduction

Interpretation:    

The balanced equation for the following half reaction has to be identified and also specify whether the reaction is an oxidation or reduction reaction.

  ${\text{c) NO}}_{\text{3}}^{\text{-}}\text{(aq) }\to \text{ NO(g) (in acid)}$

Concept Introduction:

Refer to (a)