Chapter 21, Problem

Interpretation Introduction

Interpretation:

The balanced net ionic equation for reduction of europium ion and precipitation of europium has to be written.

Concept introduction:

In net ionic equations the ions that are common on the reactant and product sides (Spectator ions) are cancelled.  These spectator ions are not participating in the chemical reactions.  The net ionic equation for the reaction between $\text{Ca}{\left(\text{OH}\right)}_{\text{2}}$ and ${\text{Na}}_{\text{2}}{\text{CO}}_{\text{3}}$ is given below.  As hydroxide ions and sodium ions are common on both the side it is neglected from the equation.

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