Question

3. Which net ionic equation describes this reaction? 3Ca(OH)2(aq) + 2FeCl3(aq) → 3CaCl2(aq) + 2Fe(OH)3(s) 3Ca2+(aq) + 3OH–(aq) + Fe3+(aq) → Fe(OH)3(s) + CaCl2(aq) Fe3+(aq) + 3OH–(aq) + 3Ca2+(aq) → Fe(OH)3(s) +3Ca2+(aq) Fe3+(aq) + 3OH–(aq) → Fe(OH)3(s) 3Ca2+(aq) + 6Cl–(aq) → 3CaCl2(aq)

Answer 1

NET Ionic equation is just looking at what makes the solid.

Fe3+(aq) + 3OH-(aq) → Fe(OH)3(s)

Answer 2

The net ionic equation comprises of only the solid state compound on the product side along with its individual ions on the reactant side.

Let us eliminate the options one by one to reach the correct answer.

Option 1.

3Ca2+(aq) + 3OH–(aq) + Fe3+(aq) → Fe(OH)3(s) + CaCl2(aq)

In the given option it can be observed that there are aqueous solutions on the products side which invalidates its authenticity to be the net ionic equation.

Option 2.

3Ca2+(aq) + 3OH–(aq) + Fe3+(aq) → Fe(OH)3(s) + CaCl2(aq)

The option 2 also contains an aqueous solution on the right end hence it cannot be a net ionic equation.

Option 3

Fe3+(aq) + 3OH–(aq) → Fe(OH)3(s)

The option 3 suffices the condition of net ionic equation where solid brown precipitate of ferric hydroxide is formed and the reactant side consists of the individual reactant ions only.