Questions: Active Exercise • When a strip of magnesium metal is placed in an iron(III) chloride solution, a magnesium chloride solution results and solid iron also forms. Develop the net ionic equation for the reaction

Active Exercise

• When a strip of magnesium metal is placed in an iron(III) chloride solution, a magnesium chloride solution results and solid iron also forms. Develop the net ionic equation for the reaction

Transcript text: Active Exercise • When a strip of magnesium metal is placed in an iron(III) chloride solution, a magnesium chloride solution results and solid iron also forms. Develop the net ionic equation for the reaction

Solution

Solution Steps

Step 1: Write the Balanced Molecular Equation

First, we write the balanced molecular equation for the reaction between magnesium metal and iron(III) chloride:

$\text{Mg (s)} + \text{2 FeCl}_3 \text{ (aq)} \rightarrow \text{3 MgCl}_2 \text{ (aq)} + \text{2 Fe (s)}$

Step 2: Write the Complete Ionic Equation

Next, we express all the soluble ionic compounds as their respective ions. Magnesium metal and solid iron remain unchanged because they are not in ionic form in the solution:

$\text{Mg (s)} + 2 \text{Fe}^{3+} \text{ (aq)} + 6 \text{Cl}^- \text{ (aq)} \rightarrow \text{3 Mg}^{2+} \text{ (aq)} + 6 \text{Cl}^- \text{ (aq)} + 2 \text{Fe (s)}$

Step 3: Cancel Spectator Ions

Spectator ions are ions that appear on both sides of the equation and do not participate in the reaction. In this case, the chloride ions ( $\text{Cl}^-$ ) are spectator ions. We cancel them out:

$\text{Mg (s)} + 2 \text{Fe}^{3+} \text{ (aq)} \rightarrow \text{3 Mg}^{2+} \text{ (aq)} + 2 \text{Fe (s)}$