Chapter 8, Problem 9PE

(a)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{MnO}}_{\text{2}}\text{+CO}\stackrel{}{\to }{\text{Mn}}_{\text{2}}{\text{CO}}_{\text{3}}{\text{+CO}}_{\text{2}}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{2MnO}}_{\text{2}}\text{+CO}\stackrel{}{\to }{\text{Mn}}_{\text{2}}{\text{CO}}_{\text{3}}{\text{+CO}}_{\text{2}}$

Explanation of Solution

The given equation is,

  ${\text{MnO}}_{\text{2}}\text{+CO}\stackrel{}{\to }{\text{Mn}}_{\text{2}}{\text{CO}}_{\text{3}}{\text{+CO}}_{\text{2}}$

Carbon is balanced.  Manganese and oxygen are not balanced.

Place the coefficient 2 in front of ${\text{MnO}}_{\text{2}}$ to balance both manganese and oxygen.  The balanced equation is,

  ${\text{2MnO}}_{\text{2}}\text{+CO}\stackrel{}{\to }{\text{Mn}}_{\text{2}}{\text{CO}}_{\text{3}}{\text{+CO}}_{\text{2}}$

Each side has 2 manganese atoms, one carbon atom and five oxygen atoms.

(b)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{Cu}}_{\text{2}}\text{O}\left(\text{s}\right)\text{+C}\left(\text{s}\right)\stackrel{}{\to }\text{Cu}\left(\text{s}\right)\text{+CO}\left(\text{g}\right)$

Answer to Problem 9PE

The balanced equation is,

  ${\text{Cu}}_{\text{2}}\text{O}\left(\text{s}\right)\text{+C}\left(\text{s}\right)\stackrel{}{\to }\text{2Cu}\left(\text{s}\right)\text{+CO}\left(\text{g}\right)$

Explanation of Solution

The given equation is,

  ${\text{Cu}}_{\text{2}}\text{O}\left(\text{s}\right)\text{+C}\left(\text{s}\right)\stackrel{}{\to }\text{Cu}\left(\text{s}\right)\text{+CO}\left(\text{g}\right)$

Carbon and oxygen are balanced.  Copper is unbalanced.

Place the coefficient 2 before $\text{Cu}$ to balance the copper atoms.

The balanced equation is,

  ${\text{Cu}}_{\text{2}}\text{O}\left(\text{s}\right)\text{+C}\left(\text{s}\right)\stackrel{}{\to }\text{2Cu}\left(\text{s}\right)\text{+CO}\left(\text{g}\right)$

Each side has two copper atoms, one oxygen atom and one carbon atom.

(c)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}\stackrel{}{\to }{\text{CO}}_{\text{2}}{\text{+H}}_{\text{2}}{\text{O+N}}_{\text{2}}{\text{+O}}_{\text{2}}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{4C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}\stackrel{}{\to }{\text{12CO}}_{\text{2}}{\text{+10H}}_{\text{2}}{\text{O+6N}}_{\text{2}}{\text{+O}}_{\text{2}}$

Explanation of Solution

The given equation is,

  ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}\stackrel{}{\to }{\text{CO}}_{\text{2}}{\text{+H}}_{\text{2}}{\text{O+N}}_{\text{2}}{\text{+O}}_{\text{2}}$

All the atoms are unbalanced.

Place the coefficient 4 before ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$ to balance carbon atoms and place the coefficient 12 before ${\text{CO}}_{\text{2}}$ to balance carbon and oxygen atoms.

Place the coefficient 4 before ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$ to balance oxygen atoms and place the coefficient 10 before ${\text{H}}_{\text{2}}\text{O}$ to balance oxygen and hydrogen atoms.

Place the coefficient 4 before ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$ to balance nitrogen atoms and place the coefficient 6 before ${\text{N}}_{\text{2}}$ to balance nitrogen atoms.

Place the coefficient 4 before ${\text{C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}$ to balance hydrogen atoms.

The balanced equation is,

  ${\text{4C}}_{\text{3}}{\text{H}}_{\text{5}}{\left({\text{NO}}_{\text{3}}\right)}_{\text{3}}\stackrel{}{\to }{\text{12CO}}_{\text{2}}{\text{+10H}}_{\text{2}}{\text{O+6N}}_{\text{2}}{\text{+O}}_{\text{2}}$

(d)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{FeS+O}}_{\text{2}}\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+SO}}_{\text{2}}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{4FeS+7O}}_{\text{2}}\stackrel{}{\to }{\text{2Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+4SO}}_{\text{2}}$

Explanation of Solution

The given equation is,

  ${\text{FeS+O}}_{\text{2}}\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+SO}}_{\text{2}}$

Place the coefficient 4 before $\text{FeS}$ to balance iron atoms and place the coefficient 2 before ${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}$ to balance iron atoms.

Place the coefficient 4 before $\text{FeS}$ to balance sulfur atoms and place the coefficient 4 before ${\text{SO}}_{\text{2}}$ to balance sulfur atoms.

Place the coefficient 7 before ${\text{O}}_{\text{2}}$ to balance oxygen atoms, place the coefficient 2 before ${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}$ to balance oxygen atoms and place the coefficient 4 before ${\text{SO}}_{\text{2}}$ to balance oxygen atoms.

The balanced equation is,

  ${\text{4FeS+7O}}_{\text{2}}\stackrel{}{\to }{\text{2Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+4SO}}_{\text{2}}$

Each side has 4 iron atoms, 4 sulfur atoms and 14 oxygen atoms.

(e)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  $\text{Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\stackrel{}{\to }{\text{CuO+NO}}_{\text{2}}{\text{+O}}_{\text{2}}$

Answer to Problem 9PE

The balanced equation is,

  $\text{2Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\stackrel{}{\to }{\text{2CuO+4NO}}_{\text{2}}{\text{+O}}_{\text{2}}$

Explanation of Solution

The given equation is,

  $\text{Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\stackrel{}{\to }{\text{CuO+NO}}_{\text{2}}{\text{+O}}_{\text{2}}$

Place the coefficient 2 before $\text{Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ to balance copper atoms and place the coefficient 2 before $\text{CuO}$ to balance copper atoms.

Place the coefficient 2 before $\text{Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ to balance nitrogen atoms and place the coefficient 4 before ${\text{NO}}_{\text{2}}$ to balance nitrogen atoms.

Place the coefficient 2 before $\text{Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}$ to balance oxygen atoms, place the coefficient 2 before $\text{CuO}$ to balance oxygen atoms and place the coefficient 4 before ${\text{NO}}_{\text{2}}$ to balance oxygen atoms.

The balanced equation is,

  $\text{2Cu}{\left({\text{NO}}_{\text{3}}\right)}_{\text{2}}\stackrel{}{\to }{\text{2CuO+4NO}}_{\text{2}}{\text{+O}}_{\text{2}}$

Each side has 2 copper atoms, 4 nitrogen atoms and 12 oxygen atoms.

(f)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{NO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{HNO}}_{\text{3}}\text{+NO}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{3NO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{2HNO}}_{\text{3}}\text{+NO}$

Explanation of Solution

The given equation is,

  ${\text{NO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{HNO}}_{\text{3}}\text{+NO}$

Place the coefficient 3 before ${\text{NO}}_{\text{2}}$ to balance nitrogen atoms and place the coefficient 2 before ${\text{HNO}}_{\text{3}}$ to balance nitrogen atoms.

Place the coefficient 2 before ${\text{HNO}}_3$ to balance hydrogen atoms.

Place the coefficient 2 before ${\text{HNO}}_3$ to balance oxygen atoms, place the coefficient 3 before ${\text{NO}}_{\text{2}}$ to balance oxygen atoms.

The balanced equation is,

  ${\text{3NO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}\stackrel{}{\to }{\text{2HNO}}_{\text{3}}\text{+NO}$

Each side has 3 nitrogen atoms, two hydrogen atoms and seven oxygen atoms.

(g)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  $\text{Fe}\left(\text{s}\right)\text{+S}\left(\text{l}\right)\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{S}}_{\text{3}}\left(\text{s}\right)$

Answer to Problem 9PE

The balanced equation is,

  $\text{2Fe}\left(\text{s}\right)\text{+3S}\left(\text{l}\right)\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{S}}_{\text{3}}\left(\text{s}\right)$

Explanation of Solution

The given equation is,

  $\text{Fe}\left(\text{s}\right)\text{+S}\left(\text{l}\right)\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{S}}_{\text{3}}\left(\text{s}\right)$

Place the coefficient 2 before $\text{Fe}$ to balance iron atoms.

Place the coefficient 3 before $\text{S}$ to balance sulfur atoms.

The balanced equation is,

  $\text{2Fe}\left(\text{s}\right)\text{+3S}\left(\text{l}\right)\stackrel{}{\to }{\text{Fe}}_{\text{2}}{\text{S}}_{\text{3}}\left(\text{s}\right)$

Each side has two iron atoms and three sulfur atoms.

(h)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{HCN+O}}_{\text{2}}\stackrel{}{\to }{\text{N}}_{\text{2}}{\text{+CO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{4HCN+5O}}_{\text{2}}\stackrel{}{\to }{\text{2N}}_{\text{2}}{\text{+4CO}}_{\text{2}}{\text{+2H}}_{\text{2}}\text{O}$

Explanation of Solution

The given equation is,

  ${\text{HCN+O}}_{\text{2}}\stackrel{}{\to }{\text{N}}_{\text{2}}{\text{+CO}}_{\text{2}}{\text{+H}}_{\text{2}}\text{O}$

Place the coefficient 4 before $\text{HCN}$ to balance hydrogen atoms and place the coefficient 2 before ${\text{H}}_{\text{2}}\text{O}$ to balance hydrogen atoms.

Place the coefficient 4 before $\text{HCN}$ to balance carbon atoms and place the coefficient 4 before ${\text{CO}}_{\text{2}}$ to balance carbon atoms.

Place the coefficient 4 before $\text{HCN}$ to balance nitrogen atoms and place the coefficient 2 before ${\text{N}}_{\text{2}}$ to balance nitrogen atoms.

Place the coefficient 5 before ${\text{O}}_{\text{2}}$ to balance oxygen atoms, place the coefficient 2 before ${\text{H}}_{\text{2}}\text{O}$ to balance oxygen atoms and place the coefficient 4 before ${\text{CO}}_{\text{2}}$ to balance oxygen atoms.

The balanced equation is,

  ${\text{4HCN+5O}}_{\text{2}}\stackrel{}{\to }{\text{2N}}_{\text{2}}{\text{+4CO}}_{\text{2}}{\text{+2H}}_{\text{2}}\text{O}$

Each side has 4 carbons, 4 nitrogen atoms, 4 carbons atoms and ten oxygen atoms.

(i)

Interpretation Introduction

Interpretation:

The given equation has to be balanced.

The equation is,

  ${\text{B}}_{\text{5}}{\text{H}}_{\text{9}}{\text{+O}}_{\text{2}}\stackrel{}{\to }{\text{B}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+H}}_{\text{2}}\text{O}$

Answer to Problem 9PE

The balanced equation is,

  ${\text{2B}}_{\text{5}}{\text{H}}_{\text{9}}{\text{+12O}}_{\text{2}}\stackrel{}{\to }{\text{5B}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+9H}}_{\text{2}}\text{O}$

Explanation of Solution

The given equation is,

  ${\text{B}}_{\text{5}}{\text{H}}_{\text{9}}{\text{+O}}_{\text{2}}\stackrel{}{\to }{\text{B}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+H}}_{\text{2}}\text{O}$

Boron atoms are balanced by placing the coefficient 2 before ${\text{B}}_{\text{5}}{\text{H}}_{\text{9}}$ and by placing the coefficient 5 before ${\text{B}}_{\text{2}}{\text{O}}_{\text{3}}.$

Hydrogen atoms are balanced by placing the coefficient 2 before ${\text{B}}_{\text{5}}{\text{H}}_{\text{9}}$ and by placing the coefficient 9 before ${\text{H}}_{\text{2}}\text{O}\text{.}$

Oxygen atoms are balanced by placing the coefficient 12 before ${\text{O}}_{\text{2}}$ and placing the coefficient 9 before ${\text{H}}_{\text{2}}\text{O}\text{.}$

The balanced equation is,

  ${\text{2B}}_{\text{5}}{\text{H}}_{\text{9}}{\text{+12O}}_{\text{2}}\stackrel{}{\to }{\text{5B}}_{\text{2}}{\text{O}}_{\text{3}}{\text{+9H}}_{\text{2}}\text{O}$

Each side has ten boron atoms, eighteen hydrogen atoms and twenty-four oxygen atoms.