Chapter 6, Problem 43QAP

Interpretation Introduction

(a)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{2KO}}_{\text{2}}{\text{(s)+2H}}_{\text{2}}\text{O(l)}\to {\text{2KOH(aq)+O}}_{\text{2}}{\text{(g)+H}}_{\text{2}}{\text{O}}_{\text{2}}\text{(aq)}$.

Explanation of Solution

The provided reaction is:

${\text{KO}}_{\text{2}}{\text{(s)+H}}_{\text{2}}\text{O(l)}\to {\text{KOH(aq)+O}}_{\text{2}}{\text{(g)+H}}_{\text{2}}{\text{O}}_{\text{2}}\text{(aq)}$

In the given equation if we place a coefficient of 2 before KO₂ and coefficient 2 to theH₂ O that is on the reactant side, and coefficient 2 is added on the product side of KOH, then the atoms are balanced with two potassium, six oxygen atom and four hydrogen atoms giving the balanced equation.

${\text{2KO}}_{\text{2}}{\text{(s)+2H}}_{\text{2}}\text{O(l)}\to {\text{2KOH(aq)+O}}_{\text{2}}{\text{(g)+H}}_{\text{2}}{\text{O}}_{\text{2}}\text{(aq)}$ g.

Interpretation Introduction

(b)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{(s)+6HNO}}_{\text{3}}\text{(aq)}\to {\text{2Fe(NO}}_{\text{3}}{\text{)}}_{\text{3}}{\text{(aq)+3H}}_{\text{2}}\text{O(l)}$.

Explanation of Solution

The given unbalanced equation is:

${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{(s)+HNO}}_{\text{3}}\text{(aq)}\to {\text{Fe(NO}}_{\text{3}}{\text{)}}_{\text{3}}{\text{(aq)+H}}_{\text{2}}\text{O(l)}$

We start with elements of ${\text{Fe(NO}}_{\text{3}}{\text{)}}_{\text{3}}$. To balance Fe, we need to place coefficient 2 before ${\text{Fe(NO}}_{\text{3}}{\text{)}}_{\text{3}}$, coefficient 6 before HNO₃ and coefficient 3 before H₂ O. So we have six hydrogen atoms, two iron, six nitrogen and six hydrogen forming the balanced equation. Thus, the balanced chemical reaction is as follows:

${\text{Fe}}_{\text{2}}{\text{O}}_{\text{3}}{\text{(s)+6HNO}}_{\text{3}}\text{(aq)}\to {\text{2Fe(NO}}_{\text{3}}{\text{)}}_{\text{3}}{\text{(aq)+3H}}_{\text{2}}\text{O(l)}$.

Interpretation Introduction

(c)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{4NH}}_{\text{3}}{\text{(g)+5O}}_{\text{2}}\text{(g)}\to {\text{4NO(g)+6H}}_{\text{2}}\text{O(g)}$.

Explanation of Solution

The given unbalanced equation is:

${\text{NH}}_{\text{3}}{\text{(g)+O}}_{\text{2}}\text{(g)}\to {\text{NO(g)+H}}_{\text{2}}\text{O(g)}$

We start by balancingNH₃. If we place a coefficient 4 before NH₃, coefficient5 before O₂, coefficient 4 before NO and coefficient 6 before H₂ O, then we have four nitrogen atoms, twelve hydrogen atoms, and ten oxygen atoms forming the balanced equation. Thus, the balanced chemical reaction will be as follows:

Interpretation Introduction

(d)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{PCl}}_{\text{5}}{\text{(l)+4H}}_{\text{2}}\text{O(l)}\to {\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}\text{(aq)+5HCl(g)}$.

Explanation of Solution

The provided equation is:

${\text{PCl}}_{\text{5}}{\text{(l)+H}}_{\text{2}}\text{O(l)}\to {\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}\text{(aq)+HCl(g)}$

The most complicated molecule is ${\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}$ because it contains the greatestnumber of elements. If we place a coefficient of 5 before HCl and 4 before H₂ O, then we have one phosphorous atom, five chlorine atom, eight hydrogen atom and four oxygen atom giving the balanced equation. The equation balanced is given as,

${\text{PCl}}_{\text{5}}{\text{(l)+4H}}_{\text{2}}\text{O(l)}\to {\text{H}}_{\text{3}}{\text{PO}}_{\text{4}}\text{(aq)+5HCl(g)}$.

Interpretation Introduction

(e)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH(l)+3O}}_{\text{2}}\text{(g)}\to {\text{2CO}}_{\text{2}}{\text{(g)+3H}}_{\text{2}}\text{O(l)}$.

Explanation of Solution

The provided equation is:

${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH(l)+O}}_{\text{2}}\text{(g)}\to {\text{CO}}_{\text{2}}{\text{(g)+H}}_{\text{2}}\text{O(l)}$

The most complicated molecule is ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}\text{OH}$ because it contains the greatestnumber of elements. We place a coefficient of 2 before CO₂, 3 before H₂ O and 3 before O₂ that gives two atoms of carbon, six atoms of hydrogen, and seven atoms of oxygen to form the balanced equation. Thus, the balanced chemical reaction is as follows:

${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH(l)+3O}}_{\text{2}}\text{(g)}\to {\text{2CO}}_{\text{2}}{\text{(g)+3H}}_{\text{2}}\text{O(l)}$.

Interpretation Introduction

(f)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

$\text{2CaO(s)+5C(s)}\to {\text{2CaC}}_{\text{2}}{\text{(s)+CO}}_{\text{2}}\text{(g)}$.

Explanation of Solution

The provided reaction is:

$\text{CaO(s)+C(s)}\to {\text{CaC}}_{\text{2}}{\text{(s)+CO}}_{\text{2}}\text{(g)}$

If we place a coefficient of 2 before CaO and CaC₂ we get,

$\text{2CaO(s)+C(s)}\to {\text{2CaC}}_{\text{2}}{\text{(s)+CO}}_{\text{2}}\text{(g)}$

We place a coefficient of 5 before C. Now, we have a balanced equation.

$\text{2CaO(s)+5C(s)}\to {\text{2CaC}}_{\text{2}}{\text{(s)+CO}}_{\text{2}}\text{(g)}$.

Interpretation Introduction

(g)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

$2\text{M}\text{o}{\text{S}}_2(s)+7{\text{O}}_2(g)\to 2\text{M}\text{o}{\text{O}}_3(s)+4\text{S}{\text{O}}_2(g)$.

Explanation of Solution

The provided reaction is:

${\text{MoS}}_{\text{2}}{\text{(s)+O}}_{\text{2}}\text{(g)}\to {\text{MoO}}_{\text{3}}{\text{(s)+SO}}_{\text{2}}\text{(g)}$

If we place a coefficient of 4 before SO₂ and 2 before MoS₂, we get:

${\text{2MoS}}_{\text{2}}{\text{(s)+O}}_{\text{2}}\text{(g)}\to {\text{MoO}}_{\text{3}}{\text{(s)+4SO}}_{\text{2}}\text{(g)}$

By placing a coefficient of 2 before MoO₃ and 7 before O₂, we have a balanced equation.

$2\text{M}\text{o}{\text{S}}_2(s)+7{\text{O}}_2(g)\to 2\text{M}\text{o}{\text{O}}_3(s)+4\text{S}{\text{O}}_2(g)$.

Interpretation Introduction

(h)

Interpretation:

The given chemical equation is to be balanced.

Concept Introduction:

In a balanced chemical reaction, the number of similar type of elements on both sides of the reaction is equal. To balance an unbalanced equation, the coefficients that are present before the compounds are changed but the subscripts in the formulas are not changed.

Answer to Problem 43QAP

${\text{FeCO}}_{\text{3}}{\text{(s)+H}}_{\text{2}}{\text{CO}}_{\text{3}}\text{(aq)}\to {\text{Fe(HCO}}_{\text{3}}{\text{)}}_{\text{2}}\text{(aq)}$.

Explanation of Solution

The provided reaction is:

${\text{FeCO}}_{\text{3}}{\text{(s)+H}}_{\text{2}}{\text{CO}}_{\text{3}}\text{(aq)}\to {\text{Fe(HCO}}_{\text{3}}{\text{)}}_{\text{2}}\text{(aq)}$

We see that all the atoms are balanced. Hence, we have a balanced equation.

${\text{FeCO}}_{\text{3}}{\text{(s)+H}}_{\text{2}}{\text{CO}}_{\text{3}}\text{(aq)}\to {\text{Fe(HCO}}_{\text{3}}{\text{)}}_{\text{2}}\text{(aq)}$.