Chapter 5, Problem 5.8E

Balance the following equations:

a. ${\text{KClO}}_{\text{3}}\left(\text{s}\right)\to \text{KCl}\left(\text{s}\right)+{\text{O}}_2\left(\text{g}\right)$

b. ${\text{C}}_{\text{2}}{\text{H}}_6\left(\text{g}\right)+{\text{O}}_{\text{2}}\left(\text{g}\right)\to {\text{CO}}_2\left(\text{g}\right)+{\text{H}}_2\text{O}\left(l\right)$

c. $\text{nitrogen}+\text{oxygen}\to \text{dinitrogen}\text{pentoxide}$

d. ${\text{MgCl}}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{MgO}\left(\text{s}\right)+\text{HCl}\left(\text{g}\right)$

e. ${\text{CaH}}_2\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\left(\text{g}\right)$

f. $\text{Al}\left(\text{s}\right)+{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)+\text{Fe}\left(\text{s}\right)$

g. $\text{aluminum}+\text{bromine}\to \text{aluminum}\text{bromide}$

h. ${\text{Hg}}_2{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right)+\text{NaCl}\left(\text{aq}\right)\to {\text{Hg}}_2{\text{Cl}}_{\text{2}}\left(\text{s}\right)+{\text{NaNO}}_3\left(\text{aq}\right)$

Interpretation Introduction

(a)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{2KClO}}_{\text{3}}\left(\text{s}\right)\to 2\text{KCl}\left(\text{s}\right)+3{\text{O}}_2\left(\text{g}\right)$.

Explanation of Solution

The given reaction is shown below.

${\text{KClO}}_{\text{3}}\left(\text{s}\right)\to \text{KCl}\left(\text{s}\right)+{\text{O}}_2\left(\text{g}\right)$

The given reaction contains one atom of potassium, one atom of chlorine and three atoms of oxygen on the left hand side. While on the right hand side, it contains one atom of potassium, one atom of chlorine and two atoms of oxygen. Therefore, the coefficient of $2$ must be placed before ${\text{KClO}}_3$, $2$ must be placed before $\text{KCl}$ and $3$ must be placed before ${\text{O}}_2$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{2KClO}}_{\text{3}}\left(\text{s}\right)\to 2\text{KCl}\left(\text{s}\right)+3{\text{O}}_2\left(\text{g}\right)$

Conclusion

The balanced equation is ${\text{2KClO}}_{\text{3}}\left(\text{s}\right)\to 2\text{KCl}\left(\text{s}\right)+3{\text{O}}_2\left(\text{g}\right)$.

Interpretation Introduction

(b)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{2C}}_{\text{2}}{\text{H}}_6\left(\text{g}\right)+7{\text{O}}_{\text{2}}\left(\text{g}\right)\to 4{\text{CO}}_2\left(\text{g}\right)+6{\text{H}}_2\text{O}\left(l\right)$.

Explanation of Solution

The given reaction is shown below.

${\text{C}}_{\text{2}}{\text{H}}_6\left(\text{g}\right)+{\text{O}}_{\text{2}}\left(\text{g}\right)\to {\text{CO}}_2\left(\text{g}\right)+{\text{H}}_2\text{O}\left(l\right)$

The given reaction contains two atoms of carbon, six atoms of hydrogen and two atoms of oxygen on the left hand side. While on the right hand side, it contains one atom of carbon, two atoms of hydrogen and three atoms of oxygen. Therefore, the coefficient of $7$ must be placed before ${\text{O}}_{\text{2}}$, $2$ must be placed before ${\text{C}}_{\text{2}}{\text{H}}_6$, $4$ must be placed before ${\text{CO}}_2$ and $6$ must be placed before ${\text{H}}_2\text{O}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{2C}}_{\text{2}}{\text{H}}_6\left(\text{g}\right)+7{\text{O}}_{\text{2}}\left(\text{g}\right)\to 4{\text{CO}}_2\left(\text{g}\right)+6{\text{H}}_2\text{O}\left(l\right)$

Conclusion

The balanced equation is ${\text{2C}}_{\text{2}}{\text{H}}_6\left(\text{g}\right)+7{\text{O}}_{\text{2}}\left(\text{g}\right)\to 4{\text{CO}}_2\left(\text{g}\right)+6{\text{H}}_2\text{O}\left(l\right)$.

Interpretation Introduction

(c)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{2N}}_2\left(\text{g}\right)+5{\text{O}}_2\left(\text{g}\right)\to 2{\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\left(\text{g}\right)$.

Explanation of Solution

The given reaction is shown below.

$\text{nitrogen}+\text{oxygen}\to \text{dinitrogen}\text{pentoxide}$

The given reaction can be written as follows:

${\text{N}}_2\left(\text{g}\right)+{\text{O}}_2\left(\text{g}\right)\to {\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\left(\text{g}\right)$

The given reaction contains two atoms of nitrogen and two atoms of oxygen on the left side. While on the right hand side, it contains two atoms of nitrogen and five atoms of oxygen. Therefore, the coefficient of $2$ must be placed before ${\text{N}}_2$, $5$ must be placed before ${\text{O}}_2$ and $2$ must be placed before ${\text{N}}_{\text{2}}{\text{O}}_{\text{5}}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{2N}}_2\left(\text{g}\right)+5{\text{O}}_2\left(\text{g}\right)\to 2{\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\left(\text{g}\right)$

Conclusion

The balanced equation is ${\text{2N}}_2\left(\text{g}\right)+5{\text{O}}_2\left(\text{g}\right)\to 2{\text{N}}_{\text{2}}{\text{O}}_{\text{5}}\left(\text{g}\right)$.

Interpretation Introduction

(d)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{MgCl}}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{MgO}\left(\text{s}\right)+2\text{HCl}\left(\text{g}\right)$.

Explanation of Solution

The given reaction is shown below.

${\text{MgCl}}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{MgO}\left(\text{s}\right)+\text{HCl}\left(\text{g}\right)$

The given reaction contains one atom of magnesium, two atoms of hydrogen, one atom of oxygen and two atoms of chlorine on the left hand side. While on the right hand side, it contains one atom of magnesium, one atom of hydrogen, one atom of oxygen and one atom of chlorine. Therefore, the coefficient of $2$ must be placed before $\text{HCl}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{MgCl}}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{MgO}\left(\text{s}\right)+2\text{HCl}\left(\text{g}\right)$

Conclusion

The balanced equation is ${\text{MgCl}}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(\text{g}\right)\to \text{MgO}\left(\text{s}\right)+2\text{HCl}\left(\text{g}\right)$.

Interpretation Introduction

(e)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{CaH}}_2\left(\text{s}\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{s}\right)+2{\text{H}}_{\text{2}}\left(\text{g}\right)$.

Explanation of Solution

The given reaction is shown below.

${\text{CaH}}_2\left(\text{s}\right)+{\text{H}}_{\text{2}}\text{O}\left(l\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{s}\right)+{\text{H}}_{\text{2}}\left(\text{g}\right)$

The given reaction contains one atom of calcium, four atoms of hydrogen and one atom of oxygen on the left hand side. While on the right hand side, it contains one atom of calcium, four atoms of hydrogen and two atoms of oxygen. Therefore, the coefficient of $2$ must be placed before ${\text{H}}_{\text{2}}\text{O}$ and $2$ must be placed before ${\text{H}}_{\text{2}}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{CaH}}_2\left(\text{s}\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{s}\right)+2{\text{H}}_{\text{2}}\left(\text{g}\right)$

Conclusion

The balanced equation is ${\text{CaH}}_2\left(\text{s}\right)+2{\text{H}}_{\text{2}}\text{O}\left(l\right)\to \text{Ca}{\left(\text{OH}\right)}_{\text{2}}\left(\text{s}\right)+2{\text{H}}_{\text{2}}\left(\text{g}\right)$.

Interpretation Introduction

(f)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is $\text{2Al}\left(\text{s}\right)+{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)+2\text{Fe}\left(\text{s}\right)$.

Explanation of Solution

The given reaction is shown below.

$\text{Al}\left(\text{s}\right)+{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)+\text{Fe}\left(\text{s}\right)$

The given reaction contains two atoms of iron, one atom of aluminum and three atoms of oxygen on the left hand side. While on the right hand side, it contains one atom of iron, two atoms of aluminum and three atoms of oxygen. Therefore, the coefficient of $2$ must be placed before $\text{Al}$ and $2$ must be placed before $\text{Fe}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

$\text{2Al}\left(\text{s}\right)+{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)+2\text{Fe}\left(\text{s}\right)$

Conclusion

The balanced equation is $\text{2Al}\left(\text{s}\right)+{\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)\to {\text{Al}}_{\text{2}}{\text{O}}_{\text{3}}\left(\text{s}\right)+2\text{Fe}\left(\text{s}\right)$.

Interpretation Introduction

(g)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is $\text{2Al}\left(\text{s}\right)+3{\text{Br}}_2\left(l\right)\to 2{\text{AlBr}}_{\text{3}}\left(l\right)$.

Explanation of Solution

The given reaction is shown below.

$\text{aluminum}+\text{bromine}\to \text{aluminum}\text{bromide}$

The given reaction can be written as follows:

$\text{Al}\left(\text{s}\right)+{\text{Br}}_2\left(l\right)\to {\text{AlBr}}_{\text{3}}\left(l\right)$

The given reaction contains one atom of aluminum and two atoms of bromine on the left hand side. While on the right hand side, it contains one atom of aluminum and three atoms of bromine. Therefore, the coefficient of $2$ must be placed before $\text{Al}$, $3$ must be placed before ${\text{Br}}_2$ and $2$ must be placed before ${\text{AlBr}}_{\text{3}}$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

$\text{2Al}\left(\text{s}\right)+3{\text{Br}}_2\left(l\right)\to 2{\text{AlBr}}_{\text{3}}\left(l\right)$

Conclusion

The balanced equation is $\text{2Al}\left(\text{s}\right)+3{\text{Br}}_2\left(l\right)\to 2{\text{AlBr}}_{\text{3}}\left(l\right)$.

Interpretation Introduction

(h)

Interpretation:

The given equation is to be balanced.

Concept introduction:

A balanced chemical equation represents an equation in which all the reactants and products are written with their stoichiometric coefficient and physical states. The number of atoms of an element on the both sides of the equation is equal.

Answer to Problem 5.8E

The balanced equation is ${\text{Hg}}_2{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right)+2\text{NaCl}\left(\text{aq}\right)\to {\text{Hg}}_2{\text{Cl}}_{\text{2}}\left(\text{s}\right)+2{\text{NaNO}}_3\left(\text{aq}\right)$.

Explanation of Solution

The given reaction is shown below.

${\text{Hg}}_2{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right)+\text{NaCl}\left(\text{aq}\right)\to {\text{Hg}}_2{\text{Cl}}_{\text{2}}\left(\text{s}\right)+{\text{NaNO}}_3\left(\text{aq}\right)$

The given reaction contains two atoms of mercury, two atoms of nitrogen, six atoms of oxygen, one atom of sodium and one atom of chlorine on the left hand side. While on the right hand side, it contains two atoms of mercury, one atom of nitrogen, three atoms of oxygen, one atom of sodium and two atoms of chlorine. Therefore, the coefficient of $2$ must be placed before $\text{NaCl}$ and $2$ must be placed before ${\text{NaNO}}_3$ to get an overall balanced chemical equation. The balanced chemical reaction is shown below.

${\text{Hg}}_2{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right)+2\text{NaCl}\left(\text{aq}\right)\to {\text{Hg}}_2{\text{Cl}}_{\text{2}}\left(\text{s}\right)+2{\text{NaNO}}_3\left(\text{aq}\right)$

Conclusion

The balanced equation is ${\text{Hg}}_2{\left({\text{NO}}_{\text{3}}\right)}_2\left(\text{aq}\right)+2\text{NaCl}\left(\text{aq}\right)\to {\text{Hg}}_2{\text{Cl}}_{\text{2}}\left(\text{s}\right)+2{\text{NaNO}}_3\left(\text{aq}\right)$.