Chapter 9.3, Problem 38PP

Interpretation Introduction

Interpretation:

The chemical, complete ionic and net ionic reaction between aqueous solution of lithium sulfate and calcium nitrate needs to be explained.

Concept introduction:

The molecular equation of a chemical reaction represents the reactant and product molecules as their molecular formula. The physical states of substances should be written in parenthesis. The ionic equation can be written in which all aqueous substance must be written as their ions.

The net ionic equation is modified form of ionic equation in which the spectator ions must be cancelled from both sides.

Answer to Problem 38PP

Net ionic equation:

$\begin{array}{l}{\text{ SO}}_{{}_{\text{4}}}^{\text{-2}}{\text{(aq) + Ca}}_{{}_{}}^{\text{+2}}\text{(aq) }\stackrel{}{\to }{\text{ CaSO}}_{\text{4}}\text{(s)}\\ \end{array}$

Explanation of Solution

Given information:

Reaction between aqueous solution of lithium sulfate and calcium nitrate forms precipitate of calcium sulfate.

The molecular reaction equation between aqueous solution of lithium sulfate and calcium nitrate can be written as:

${\text{ Li}}_{\text{2}}{\text{SO}}_{\text{4}}{\text{(aq) + Ca(NO}}_{\text{3}}{\text{)}}_{\text{2}}\text{(aq)}\stackrel{}{\to }{\text{ 2 LiNO}}_{\text{3}}{\text{(aq) + CaSO}}_{\text{4}}\text{(s)}$

Since all compounds are in aqueous state so ionic equation must be:

$\begin{array}{l}{\text{2 Li}}_{{}_{}}^{\text{+}}{\text{(aq)+ SO}}_{{}_{\text{4}}}^{\text{-2}}{\text{(aq) + Ca}}_{{}_{}}^{\text{+2}}{\text{(aq) + 2 NO}}_{{}_{\text{3}}}^{\text{-}}\text{(aq) }\stackrel{}{\to }{\text{2 Li}}_{{}_{}}^{\text{+}}{\text{(aq)+ 2 NO}}_{{}_{\text{3}}}^{\text{-}}{\text{(aq) + CaSO}}_{\text{4}}\text{(s)}\\ \end{array}$

Here calcium sulfate is in solid state and Li+ and NO₃- ions are spectator ions therefore the net ionic equation can be written as:

$\begin{array}{l}{\text{ SO}}_{{}_{\text{4}}}^{\text{-2}}{\text{(aq) + Ca}}_{{}_{}}^{\text{+2}}\text{(aq) }\stackrel{}{\to }{\text{ CaSO}}_{\text{4}}\text{(s)}\\ \end{array}$

Conclusion

Net ionic equation:

$\begin{array}{l}{\text{ SO}}_{{}_{\text{4}}}^{\text{-2}}{\text{(aq) + Ca}}_{{}_{}}^{\text{+2}}\text{(aq) }\stackrel{}{\to }{\text{ CaSO}}_{\text{4}}\text{(s)}\\ \end{array}$