Chapter 8, Problem 28A

(a)

Interpretation Introduction

Interpretation: The given oxidation-reduction reaction needs to be balanced.

  ${\text{K}}_{\text{(s)}}{\text{ + F}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ KF}}_{\text{(s)}}$

Concept Introduction: A chemical reaction can be described as the process of conversion of reactant molecules to product molecules by breaking and making of chemical bonds.

A balance chemical reaction contains same number of atoms at both sides of the chemical reaction.

Answer to Problem 28A

  ${\text{2 K}}_{\text{(s)}}{\text{ + F}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 KF}}_{\text{(s)}}$

Explanation of Solution

In a balance chemical equation, the number of atoms must be same at both sides. To balance a chemical reaction, coefficients must be added with the chemical formula to make it same at both sides.

Reactant	Product
K= 1→ 2	K = 1→ 2
F = 2	F = 1→ 2

Thus the balance chemical equation must be:

  ${\text{2 K}}_{\text{(s)}}{\text{ + F}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 KF}}_{\text{(s)}}$

(b)

Interpretation Introduction

Interpretation: The given oxidation-reduction reaction needs to be balanced.

  ${\text{K}}_{\text{(s)}}{\text{ + O}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ K}}_{\text{2}}{\text{O}}_{\text{(s)}}$

Concept Introduction: A chemical reaction can be describe as the process of conversion of reactant molecules to product molecules by breaking and making of chemical bonds.

A balance chemical reaction contains same number of atoms at both sides of the chemical reaction.

Answer to Problem 28A

  ${\text{4 K}}_{\text{(s)}}{\text{ + O}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 K}}_{\text{2}}{\text{O}}_{\text{(s)}}$

Explanation of Solution

In a balance chemical equation, the number of atoms must be same at both sides. To balance a chemical reaction, coefficients must be added with the chemical formula to make it same at both sides.

Reactant	Product
K= 1→4	K = 2→4
O = 2	O = 2

Thus the balance chemical equation must be:

  ${\text{4 K}}_{\text{(s)}}{\text{ + O}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 K}}_{\text{2}}{\text{O}}_{\text{(s)}}$

(c)

Interpretation Introduction

Interpretation: The given oxidation-reduction reaction needs to be balanced.

  ${\text{K}}_{\text{(s)}}{\text{ + N}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ K}}_{\text{3}}{\text{N}}_{\text{(s)}}$

Concept Introduction: A chemical reaction can be described as the process of conversion of reactant molecules to product molecules by breaking and making of chemical bonds.

A balance chemical reaction contains same number of atoms at both sides of the chemical reaction.

Answer to Problem 28A

  ${\text{6 K}}_{\text{(s)}}{\text{ + N}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 K}}_3{\text{N}}_{\text{(s)}}$

Explanation of Solution

In a balance chemical equation, the number of atoms must be same at both sides. To balance a chemical reaction, coefficients must be added with the chemical formula to make it same at both sides.

Reactant	Product
K= 1→6	K = 3→6
N = 2	N = 1→2

Thus the balance chemical equation must be:

  ${\text{6 K}}_{\text{(s)}}{\text{ + N}}_{\text{2}}{}_{\text{(g) }}\stackrel{}{\to }{\text{ 2 K}}_3{\text{N}}_{\text{(s)}}$

(d)

Interpretation Introduction

Interpretation: The given oxidation-reduction reaction needs to be balanced.

  ${\text{K}}_{\text{(s)}}{\text{ + C}}_{\text{(g) }}\stackrel{}{\to }{\text{ K}}_{\text{4}}{\text{C}}_{\text{(s)}}$

Concept Introduction: A chemical reaction can be described as the process of conversion of reactant molecules to product molecules by breaking and making of chemical bonds.

A balance chemical reaction contains same number of atoms at both sides of the chemical reaction.

Answer to Problem 28A

  ${\text{ 4 K}}_{\text{(s)}}{\text{ + C}}_{\text{(g) }}\stackrel{}{\to }{\text{ K}}_4{\text{C}}_{\text{(s)}}$

Explanation of Solution

In a balance chemical equation, the number of atoms must be same at both sides. To balance a chemical reaction, coefficients must be added with the chemical formula to make it same at both sides.

Reactant	Product
K= 1→4	K = 4
C = 1	C = 1

Thus the balance chemical equation must be:

  ${\text{ 4 K}}_{\text{(s)}}{\text{ + C}}_{\text{(g) }}\stackrel{}{\to }{\text{ K}}_4{\text{C}}_{\text{(s)}}$