The reaction of Zinc chloride (ZnCl2) with sodium hydroxide (NaOH) is a classic example of an acid-base reaction. In this reaction, Zinc chloride reacts with sodium hydroxide to form Zinc hydroxide (Zn(OH)2) and sodium chloride (NaCl) as products. The balanced chemical equation for this reaction is as follows:
ZnCl2(aq) + 2NaOH(aq) → Zn(OH)2(s) + 2NaCl(aq)
The above equation gives us an overall picture of what happens in the reaction, but it does not give us a complete understanding of the chemical processes involved. This is where net ionic equations come in handy.
A net ionic equation is a simplified form of a chemical equation that shows only the species that are directly involved in the reaction. It excludes spectator ions, which are present in the reaction mixture but do not participate in the reaction. Spectator ions are ions that do not change oxidation state or composition during the reaction.
To write a net ionic equation for the reaction of ZnCl2 with NaOH, we need to first write the balanced chemical equation and then identify the ions that are present in the reaction mixture. In this case, we have the following balanced chemical equation:
ZnCl2(aq) + 2NaOH(aq) → Zn(OH)2(s) + 2NaCl(aq)
The aqueous solutions of ZnCl2 and NaOH contain the following ions:
ZnCl2(aq) → Zn2+(aq) + 2Cl-(aq) NaOH(aq) → Na+(aq) + OH-(aq)
When these two solutions are mixed, the following reaction occurs:
Zn2+(aq) + 2OH-(aq) → Zn(OH)2(s)
The reaction between Zn2+ and OH- ions produces Zinc hydroxide as a solid precipitate. The Chloride (Cl-) and Sodium (Na+) ions do not participate in the reaction and remain in the solution as spectator ions. Thus, the net ionic equation for the reaction of ZnCl2 with NaOH can be written as follows:
Zn2+(aq) + 2OH-(aq) → Zn(OH)2(s)
The net ionic equation shows only the species that participate in the reaction and are directly involved in the formation of the product. The spectator ions, Na+ and Cl-, are not included in the net ionic equation because they do not react or undergo any chemical change during the reaction.
In summary, the reaction of Zinc chloride with sodium hydroxide produces Zinc hydroxide and sodium chloride as products. The balanced chemical equation for the reaction is ZnCl2(aq) + 2NaOH(aq) → Zn(OH)2(s) + 2NaCl(aq). The net ionic equation for the reaction is Zn2+(aq) + 2OH-(aq) → Zn(OH)2(s). The net ionic equation only shows the species that participate in the reaction and excludes spectator ions. The net ionic equation gives us a better understanding of the chemical processes involved in the reaction and helps us to focus on the important species that participate in the reaction.