Chapter 15, Problem 1E

Complete the changes in concentrations for each of the following reactions:

(a) $\begin{array}{l}\text{AgI}\left(s\right)\to {\text{Ag}}^{+}\left(aq\right)+{\text{I}}^{-}\left(aq\right)\\ x\end{array}$

(b) $\begin{array}{l}{\text{CaCO}}_3\left(s\right)\to {\text{Ca}}^{2+}\left(aq\right)+{\text{CO}}_3{}^{2-}\left(aq\right)\\ x\end{array}$

(c) $\begin{array}{l}{\text{Mg}}_3{\left(\text{OH}\right)}_2\left(s\right)\to {\text{Mg}}^{2+}\left(aq\right)+2{\text{OH}}^{-}\left(aq\right)\\ x\end{array}$

(d) $\begin{array}{l}{\text{Mg}}_3{\left({\text{PO}}_4\right)}_2\left(s\right)\to 3{\text{Mg}}^{2+}\left(aq\right)+2{\text{PO}}_4{}^{3-}\left(aq\right)\\ x\end{array}$

(e) $\begin{array}{l}{\text{Ca}}_5{\left({\text{PO}}_4\right)}_3\text{OH}\left(s\right)\text{OH}\left(s\right)\to 5{\text{Ca}}^{2+}\left(aq\right)+3{\text{PO}}_4{}^{3-}\left(aq\right)+{\text{OH}}^{-}\left(aq\right)\\ x\end{array}$

Interpretation Introduction

Interpretation: The change in the concentration of products for the provided reaction should be written.

  $\begin{array}{l}\text{AgI}(s)\stackrel{}{\to }{\text{Ag}}^{+}(aq)+{\text{I}}^{-}(aq)\\ x\_\_\_\end{array}$

Concept introduction: Chemical reaction is defined as the reaction in which reactants (on the left side) are converted into products (on the right side).

Answer to Problem 1E

The changes in the concentration of each ion for the provide reaction is as follows:

  $\begin{array}{l}\text{AgI}(s)\stackrel{}{\to }{\text{Ag}}^{+}(aq)+{\text{I}}^{-}(aq)\\ -x+x+x\end{array}$

Explanation of Solution

The change in concentration is positive for the formation of the product as it results in an increase in the concentration of products during the reaction, whereas the change in concentration is negative for the reactants as, during the reaction, the reactants are consumed in order to form the products.

Therefore, the change in the concentrations for the provided reaction is:

  $\begin{array}{l}\text{AgI}(s)\stackrel{}{\to }{\text{Ag}}^{+}(aq)+{\text{I}}^{-}(aq)\\ -x+x+x\end{array}$

Interpretation Introduction

Interpretation: The change in the concentration of products for the provided reaction should be written.

  $\begin{array}{l}{\text{CaCO}}_{\text{3}}(s)\stackrel{}{\to }{\text{Ca}}^{2+}(aq)+{\text{CO}}_3{}^{2-}(aq)\\ \_\_\_\_x\end{array}$

Concept introduction: Chemical reaction is defined as the reaction in which reactants (on the left side) are converted into products (on the right side).

Answer to Problem 1E

The changes in the concentration of each ion for the provide reaction is as follows:

  $\begin{array}{l}{\text{CaCO}}_{\text{3}}(s)\stackrel{}{\to }{\text{Ca}}^{2+}(aq)+{\text{CO}}_3{}^{2-}(aq)\\ -x+x+x\end{array}$

Explanation of Solution

The change in concentration is positive for the formation of the product as it results in an increase in the concentration of products during the reaction, whereas the change in concentration is negative for the reactants as, during the reaction, the reactants are consumed in order to form the products.

Therefore, the change in the concentrations for the provided reaction is

  $\begin{array}{l}{\text{CaCO}}_{\text{3}}(s)\stackrel{}{\to }{\text{Ca}}^{2+}(aq)+{\text{CO}}_3{}^{2-}(aq)\\ -x+x+x\end{array}$

Interpretation Introduction

Interpretation: The change in the concentration of products for the provided reaction should be written.

  $\begin{array}{l}{\text{Mg(OH)}}_2(s)\stackrel{}{\to }{\text{Mg}}^{2+}(aq)+\text{2}{\text{HO}}^{-}(aq)\\ x\_\_\_\_\end{array}$

Concept introduction: Chemical reaction is defined as the reaction in which reactants (on the left side) are converted into products (on the right side).

Answer to Problem 1E

The changes in the concentration of each ion for the provide reaction is as follows:

  $\begin{array}{l}{\text{Mg(OH)}}_2(s)\stackrel{}{\to }{\text{Mg}}^{2+}(aq)+\text{2}{\text{HO}}^{-}(aq)\\ -x+x+2x\end{array}$

Explanation of Solution

The change in concentration is positive for the formation of the product as it results in an increase in the concentration of products during the reaction, whereas the change in concentration is negative for the reactants as, during the reaction, the reactants are consumed in order to form the products.

In the provided reaction, the change in concentration of hydroxide ion is double hence its change is 2x.

Therefore, the change in the concentrations for the provided reaction is

  $\begin{array}{l}{\text{Mg(OH)}}_2(s)\stackrel{}{\to }{\text{Mg}}^{2+}(aq)+\text{2}{\text{HO}}^{-}(aq)\\ -x+x+2x\end{array}$

Interpretation Introduction

Interpretation: The change in the concentration of products for the provided reaction should be written.

  $\begin{array}{l}{\text{Mg}}_3{{\text{(PO}}_4}_{\text{)}}(s)\stackrel{}{\to }3{\text{Mg}}^{2+}(aq)+\text{2}{\text{PO}}_4{}^{3-}(aq)\\ x\_\_\_\_\_\_\end{array}$

Concept introduction: Chemical reaction is defined as the reaction in which reactants (on left side) are converted into products (on right side).

Answer to Problem 1E

The changes in the concentration of each ion for the provide reaction is as follows:

  $\begin{array}{l}{\text{Mg}}_3{{\text{(PO}}_4}_{\text{)}}(s)\stackrel{}{\to }3{\text{Mg}}^{2+}(aq)+\text{2}{\text{PO}}_4{}^{3-}(aq)\\ -x+3x+2x\end{array}$

Explanation of Solution

The change in concentration is positive for the formation of product as it results in an increase in the concentration of products during the reaction, whereas the change in concentration is negative for the reactants as, during the reaction, the reactants are consumed in order to form the products.

In the provided reaction, the change in concentration of magnesium ion is triple and phosphate ion is double hence its change is 3x and 2x respectively

Therefore, the change in the concentrations for the provided reaction is

  $\begin{array}{l}{\text{Mg}}_3{{\text{(PO}}_4}_{\text{)}}(s)\stackrel{}{\to }3{\text{Mg}}^{2+}(aq)+\text{2}{\text{PO}}_4{}^{3-}(aq)\\ -x+3x+2x\end{array}$

Interpretation Introduction

Interpretation: The change in the concentration of products for the provided reaction should be written.

  $\begin{array}{l}{\text{Ca}}_5{{\text{(PO}}_4}_{\text{)}}\text{OH}(s)\stackrel{}{\to }5{\text{Ca}}^{2+}(aq)+\text{3}{\text{PO}}_4{}^{3-}(aq)+{\text{HO}}^{-}(aq)\\ xx\text{ \_\_\_\_}\end{array}$

Concept introduction: Chemical reaction is defined as the reaction in which reactants (on left side) are converted into products (on right side).

Answer to Problem 1E

The changes in the concentration of each ion for the provide reaction is as follows:

  $\begin{array}{l}{\text{Ca}}_5{{\text{(PO}}_4}_{\text{)}}\text{OH}(s)\stackrel{}{\to }5{\text{Ca}}^{2+}(aq)+\text{3}{\text{PO}}_4{}^{3-}(aq)+{\text{HO}}^{-}(aq)\\ -x+5x+3x+x\end{array}$

Explanation of Solution

The change in concentration is positive for the formation of product as it results in increase in the concentration of products during the reaction, whereas the change in concentration is negative for the reactants as, during the reaction, the reactants are consumed in order to form the products.

In the provided reaction, the change in concentration of calcium ion is penta time and phosphate ion is triple and hydroxide ion is mono hence its change is 5x, 3x, and x respectively

Therefore, the change in the concentrations for the provided reaction is

  $\begin{array}{l}{\text{Ca}}_5{{\text{(PO}}_4}_{\text{)}}\text{OH}(s)\stackrel{}{\to }5{\text{Ca}}^{2+}(aq)+\text{3}{\text{PO}}_4{}^{3-}(aq)+{\text{HO}}^{-}(aq)\\ -x+5x+3x+x\end{array}$