Chapter 8, Problem 42A

(a)

Interpretation Introduction

Interpretation:

The net ionic equation for the precipitation reaction in (a), if possible needs to be determined.

Concept Introduction : A precipitate is formed if two aqueous solutions are mixed to form an insoluble salt.

Answer to Problem 42A

No reaction occurs.

Explanation of Solution

Precipitation reaction does not occur between NaNO₃ and Ru(NO₃)₂as both compounds are water-soluble and single anion (NO₃-) present no displacement reaction occurs.

(b)

Interpretation Introduction

Interpretation:

The net ionic equation for the precipitation reaction in (b), if possible needs to be determined.

Concept Introduction : A precipitate is formed if two aqueous solutions are mixed to form an insoluble salt.

Answer to Problem 42A

The net ionic equation is

  ${\text{Cu}}^{2+}\left(aq\right)+{\text{ S}}^{2-}\left(aq\right)\to \text{ CuS}\left(s\right)$

Explanation of Solution

When aqueous solution of CuSO₄ is mixed with Na₂S, CuS will precipitate after double displacement reaction or precipitation reaction.

The net ionic equation is represented as follows:

  ${\text{Cu}}^{2+}\left(aq\right)+{\text{ S}}^{2-}\left(aq\right)\to \text{ CuS}\left(s\right)$

Here, CuS is insoluble in water.

(c)

Interpretation Introduction

Interpretation:

The net ionic equation for the precipitation reaction in (c), if possible needs to be determined.

Concept Introduction : A precipitate is formed if two aqueous solutions are mixed to form an insoluble salt.

Answer to Problem 42A

The net ionic reaction:

  ${\text{Pb}}^{2+}\left(aq\right)+{\text{ 2Cl}}^{-}\left(aq\right)\to {\text{ PbCl}}_{\text{2}}\left(s\right)$

Explanation of Solution

When the aqueous solution of LiCl is mixed with an aqueous solution of Pb(NO₃)₂, PbCl₂ will precipitate.

The net ionic reaction

  ${\text{Pb}}^{2+}\left(aq\right)+{\text{ 2Cl}}^{-}\left(aq\right)\to {\text{ PbCl}}_{\text{2}}\left(s\right)$

Here, PbCl₂ is insoluble in water.

(d)

Interpretation Introduction

Interpretation:

The net ionic equation for the precipitation reaction in (d), if possible needs to be determined.

Concept Introduction : A precipitate is formed if two aqueous solutions are mixed to form an insoluble salt.

Answer to Problem 42A

The net ionic reaction:

  ${\text{Ca}}^{2+}\left(aq\right)+{\text{ CO}}_3{}^{2-}\left(aq\right)\to {\text{ CaCO}}_{\text{3}}\left(s\right)$

Explanation of Solution

When calcium nitrate and lithium carbonate solutions are mixed, a double displacement reaction is possible and the formation of calcium carbonate and lithium nitrate takes place. The lithium nitrate is soluble in water but calcium carbonate is not soluble thus, a precipitate is formed.

The net ionic reaction:

  ${\text{Ca}}^{2+}\left(aq\right)+{\text{ CO}}_3{}^{2-}\left(aq\right)\to {\text{ CaCO}}_{\text{3}}\left(s\right)$

(e)

Interpretation Introduction

Interpretation:

The net ionic equation for the precipitation reaction in (e), if possible needs to be determined.

Concept Introduction : A precipitate is formed if two aqueous solutions are mixed to form an insoluble salt.

Answer to Problem 42A

Net ionic reaction :

  ${\text{Au}}^{3+}\left(aq\right)+3{\text{OH}}^{-}\left(aq\right)\to \text{ Au}{\left(\text{OH}\right)}_{\text{3}}\left(s\right)$

Explanation of Solution

When an aqueous solution of gold (III) chloride and sodium hydroxide are mixed, a double displacement reaction takes place. This results in the formation of gold (III) hydroxide and sodium chloride. Here, sodium chloride is soluble in water but gold (III) hydroxide is not soluble thus, forms precipitate.

Net ionic reaction :

  ${\text{Au}}^{3+}\left(aq\right)+3{\text{OH}}^{-}\left(aq\right)\to \text{ Au}{\left(\text{OH}\right)}_{\text{3}}\left(s\right)$