Chapter 11, Problem 50A

(a)

Interpretation Introduction

Interpretation:

The balanced chemical equation needs to be determined for a double replacement reaction that occurs in an aqueous solution when zinc sulfide is added to sulfuric acid.

Concept Introduction :

An exchange of positive ions between the two aqueous solutions AB + CD which results in CB + AD is the general form of the double replacement reaction.

Answer to Problem 50A

The balanced chemical equation is $\text{ZnS}\left(\text{aq}\right)+{\text{H}}_2{\text{SO}}_4\left(\text{aq}\right)\to {\text{H}}_{\text{2}}\text{S}\left(\text{g}\right)+{\text{ZnSO}}_{\text{4}}\left(\text{aq}\right)$ .

Explanation of Solution

When zinc sulfide $\text{ZnS}\left(\text{aq}\right)$ is added to sulfuric acid ${\text{HSO}}_4\left(\text{aq}\right)$ , which is a double replacement reaction, so, one follows the form of $\text{AB}+\text{CD}\to \text{CB}+\text{AD}$ where $\text{AB}=\text{ZnS},{\text{CD = H}}_2{\text{SO}}_4$ so the result is as $\text{CB + AD}$ .

Here, $\text{CB}={\text{H}}_{\text{2}}\text{S}\left(\text{g}\right){\text{,AD = ZnSO}}_{\text{4}}\left(\text{aq}\right)$ .

Hence, the balanced chemical equation is $\text{ZnS}\left(\text{aq}\right)+{\text{H}}_2{\text{SO}}_4\left(\text{aq}\right)\to {\text{H}}_{\text{2}}\text{S}\left(\text{g}\right)+{\text{ZnSO}}_{\text{4}}\left(\text{aq}\right)$ .

(b)

Interpretation Introduction

Interpretation:

The balanced chemical equation needs to be determined for the double replacement reaction that occurs in an aqueous solution when sodium hydroxide reacts with nitric acid.

Concept Introduction :

An exchange of positive ions between the two aqueous solutions AB + CD which results in CB + AD is the general form of the double replacement reaction.

Answer to Problem 50A

The balanced chemical equation is $\text{NaOH}\left(\text{aq}\right)+{\text{HNO}}_3\left(\text{aq}\right)\to {\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)+{\text{NaNO}}_3\left(\text{aq}\right)$ .

Explanation of Solution

When sodium hydroxide $\text{NaOH}\left(\text{aq}\right)$ is reacted with nitric acid ${\text{HNO}}_3\left(\text{aq}\right)$ , which is a double replacement reaction, so, one follows the form of $\text{AB}+\text{CD}\to \text{CB}+\text{AD}$ where $\text{AB}=\text{NaOH},{\text{CD = HNO}}_3$ so the result is as $\text{CB + AD}$ .

Here, $\text{CB}={\text{H}}_{\text{2}}{\text{O, AD = NaNO}}_3$ .

Hence, the balanced chemical equation is $\text{NaOH}\left(\text{aq}\right)+{\text{HNO}}_3\left(\text{aq}\right)\to {\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)+{\text{NaNO}}_3\left(\text{aq}\right)$ .

(c)

Interpretation Introduction

Interpretation:

The balanced chemical equation needs to be determined for a double replacement reaction that occurs in an aqueous solution when solutions of potassium fluoride and calcium nitrate are mixed.

Concept Introduction :

An exchange of positive ions between the two aqueous solutions AB + CD which results in CB + AD is the general form of the double replacement reaction.

Answer to Problem 50A

The balanced chemical equation is $\text{2KF}\left(\text{aq}\right)+\text{Ca}{\left({\text{NO}}_3\right)}_2\left(\text{aq}\right)\to {\text{CaF}}_2\left(s\right)+2{\text{KNO}}_3\left(\text{aq}\right)$ .

Explanation of Solution

When potassium fluoride $\text{KF}$ and calcium nitrate $\text{Ca}{\left({\text{NO}}_3\right)}_2$ are mixed, which is a double replacement reaction, so one follows the form of $\text{AB}+\text{CD}\to \text{CB}+\text{AD}$ where $\text{AB}=\text{KF,CD = Ca}{\left({\text{NO}}_3\right)}_2$ so the result is as $\text{CB + AD}$ .

Here, $\text{CB}={\text{CaF}}_2\text{, AD = }2{\text{KNO}}_3$ .

Hence, the balanced chemical equation is $\text{2KF}\left(\text{aq}\right)+\text{Ca}{\left({\text{NO}}_3\right)}_2\left(\text{aq}\right)\to {\text{CaF}}_2\left(s\right)+2{\text{KNO}}_3\left(\text{aq}\right)$ .