   # Balance the following redox equations. All occur in basic solution. (a) Fe(OH) 3 (s) + Cr(s) → Cr(OH) 3 (s) + Fe(OH) 2 (s) (b) NiO 2 (s) + Zn(s) → Ni(OH) 2 (s) + Zn(OH) 2 (s) (c) Fe(OH) 2 (s) + CrO 4 2− (aq) → Fe(OH) 3 (s) + [Cl(OH) 4 ] − (aq) (d) N 2 H 4 (aq) + Ag 2 O(s) → N 2 (g) + Ag(s) ### Chemistry & Chemical Reactivity

9th Edition
John C. Kotz + 3 others
Publisher: Cengage Learning
ISBN: 9781133949640

#### Solutions

Chapter
Section ### Chemistry & Chemical Reactivity

9th Edition
John C. Kotz + 3 others
Publisher: Cengage Learning
ISBN: 9781133949640
Chapter 19, Problem 6PS
Textbook Problem
5 views

## Balance the following redox equations. All occur in basic solution. (a) Fe(OH)3(s) + Cr(s) → Cr(OH)3(s) + Fe(OH)2(s) (b) NiO2(s) + Zn(s) → Ni(OH)2(s) + Zn(OH)2(s) (c) Fe(OH)2(s) + CrO42−(aq) → Fe(OH)3(s) + [Cl(OH)4]−(aq) (d) N2H4(aq) + Ag2O(s) → N2(g) + Ag(s)

a)

Interpretation Introduction

Interpretation:

The given redox equation in basic solution has to be balanced.

a) Fe(OH)3(s) + Cr(s)  Cr(OH)3(s) + Fe(OH)2(s)

Concept introduction:

Steps for balancing half –reactions in BASIC solution:

1. 1. Recognize the reaction as an oxidation and reduction reaction.
2. 2. Separate two half reactions.
3. 3.  Balance half reactions by mass

Balance all atoms except H and O in half reaction.

Addition of OH- or OH- and H2O is required for mass balance in both half reactions.

4. 4. Balance the charge by adding electrons to side with more total positive charge.
5. 5. Multiply the half reactions by appropriate factors.
6. 6. Add two half reactions and cancel the common atoms.
7. 7. Simplify by eliminating reactants and products that appears on both sides.

### Explanation of Solution

The given reaction is s follows.

Fe(OH)3(s) + Cr(s) Cr(OH)3(s) + Fe(OH)2(s)

Oxidation states:

Fe(OH)3              Cr(OH)3               Fe(OH)2x + 3(-2+1)= 0     x + 3(-2+1)= 0      x+2(-2+1)= 0x + 3(-1)= 0          x +3(-1) = 0          x+2(-1)=0x = +3                       x = +3                x=+2

Steps for balancing half –reactions in BASIC solution:

1. 1. Recognize the reaction as an oxidation and reduction reaction.

From the given reaction, Cr increases their oxidation state 0 to +3. Therefore, it is an oxidation state.

Fe decrease their oxidation state +3 to +2.Therefore, it is a reduction reaction.

2. 2. Separate two half reactions.

Oxidation: Cr(s)  Cr(OH)3(s)Reduction:Fe(OH)3(s) Fe(OH)2(s)

3. 3.  Balance half reactions for mass

Balance all atoms except H and O in half reaction.

Oxidation: Cr(s)  Cr(OH)3(s)Reduction:Fe(OH)3(s) Fe(OH)2(s)

Addition of OH- or OH- and H2O is required for mass balance in both half reactions.

Oxidation: Cr(s) +3OH-(aq) Cr(OH)3(s)Reduction:Fe(OH)3(s)  Fe(OH)2(s)+OH-(aq)

4. 4

b)

Interpretation Introduction

Interpretation:

The given redox equation in basic solution has to be balanced.

b) NiO2(s) + Zn(s) Ni(OH)2(s) + Zn(OH)2(s)

Concept introduction:

Steps for balancing half –reactions in BASIC solution:

1. 1. Recognize the reaction as an oxidation and reduction reaction.
2. 2. Separate two half reactions.
3. 3.  Balance half reactions by mass

Balance all atoms except H and O in half reaction.

Addition of OH- or OH- and H2O is required for mass balance in both half reactions.

4. 4. Balance the charge by adding electrons to side with more total positive charge.
5. 5. Multiply the half reactions by appropriate factors.
6. 6. Add two half reactions and cancel the common atoms.
7. 7. Simplify by eliminating reactants and products that appears on both sides.

c)

Interpretation Introduction

Interpretation:

The given redox equation in basic solution has to be balanced.

c) Fe(OH)2(s) + CrO42-(aq) Fe(OH)3(s) + [Cr(OH)4]-(aq)

Concept introduction:

Steps for balancing half –reactions in BASIC solution:

1. 1. Recognize the reaction as an oxidation and reduction reaction.
2. 2. Separate two half reactions.
3. 3.  Balance half reactions by mass

Balance all atoms except H and O in half reaction.

Addition of OH- or OH- and H2O is required for mass balance in both half reactions.

4. 4. Balance the charge by adding electrons to side with more total positive charge.
5. 5. Multiply the half reactions by appropriate factors.
6. 6. Add two half reactions and cancel the common atoms.
7. 7. Simplify by eliminating reactants and products that appears on both sides.

d)

Interpretation Introduction

Interpretation:

The given redox equation in basic solution has to be balanced.

d) N2H4(aq) + Ag2O(s) N2(g) + Ag(s)

Concept introduction:

Steps for balancing half –reactions in BASIC solution:

1. 1. Recognize the reaction as an oxidation and reduction reaction.
2. 2. Separate two half reactions.
3. 3.  Balance half reactions by mass

Balance all atoms except H and O in half reaction.

Addition of OH- or OH- and H2O is required for mass balance in both half reactions.

4. 4. Balance the charge by adding electrons to side with more total positive charge.
5. 5. Multiply the half reactions by appropriate factors.
6. 6. Add two half reactions and cancel the common atoms.
7. 7. Simplify by eliminating reactants and products that appears on both sides.

### Still sussing out bartleby?

Check out a sample textbook solution.

See a sample solution

#### The Solution to Your Study Problems

Bartleby provides explanations to thousands of textbook problems written by our experts, many with advanced degrees!

Get Started

Find more solutions based on key concepts
Magnesium a. assists in the operation of enzymes. b. is needed for the release and use of energy. c. is critica...

Nutrition: Concepts and Controversies - Standalone book (MindTap Course List)

A salt does not release ________ in water. a. ions b. H+

Biology: The Unity and Diversity of Life (MindTap Course List)

How do some variable stars confirm that stars have evolved?

Foundations of Astronomy (MindTap Course List)

Is Earths present atmosphere similar to or different from its first atmosphere?

Oceanography: An Invitation To Marine Science, Loose-leaf Versin

A satellite of mass 200 kg is placed into Earth orbit at a height of 200 km above the surface. (a) Assuming a c...

Physics for Scientists and Engineers, Technology Update (No access codes included) 