Chapter 9, Problem 94A

Interpretation Introduction

Interpretation:

The term spectator ion needs to be explained.

Concept introduction:

Chemical reaction is the actual process in which atoms of one or more substances rearrange to form new substances.

Answer to Problem 94A

The ions existing in the solution that occurs in a chemical reaction but not actually involved in a chemical reaction are termed as spectator ions.

Explanation of Solution

The ion which is exist in the solution that occurs a chemical reaction but not actually involve in the chemical reaction are termed as spectator ions. Spectator ions are present in both sides of a complete ionic equation; they are eliminated in a net ionic equation. For example:

$2{\text{Na}}^{+}\left(aq\right)+2{\text{Cl}}^{-}\left(aq\right)+{\text{Cu}}^{2+}\left(aq\right)+{\text{SO}}_4{}^{2-}\left(aq\right)\to 2{\text{Na}}^{+}\left(aq\right)+{\text{SO}}_4{}^{2-}\left(aq\right)+{\text{CuCl}}_2\left(s\right)$

After cancelling sulfate and sodium ion only copper and chloride ions are left in net ion equation. The reaction is as follows:

$2{\text{Cl}}^{-}\left(aq\right)+{\text{Cu}}^{2+}\left(aq\right)\to {\text{CuCl}}_2\left(s\right)$

Conclusion

Spectator ions are present in both sides of a complete ionic equation; they are eliminated in a net ionic equation.