A net ionic equation is an ionic equation where the spectator ions have been eliminated. In chemistry, a chemical equation is a symbolic representation of a chemical reaction.
When two chemical substances react, products are generated from the reaction. This is represented as a chemical equation with reactants listed on the left side of the equation and the products on the right side. In the equation, the two are separated by an arrow. For example, the chemical equation for the reaction between zinc and hydrochloric acid is as follows:
Zn + HCl → ZnCl2 + H2
According to the equation, the reactants yield zinc chloride and hydrogen gas.
In the case of an ionic equation, the electrolytes are written as dissociated ions. These types of equations are used for double displacement or single reactions that take place in aqueous solutions. An example of a full ionic equation for a reaction is as follows:
Reaction: CaCl2(aq) + 2 AgNO3(aq) → Ca(NO3)2(aq) + 2 AgCl(s)
Full ionic reaction: Ca2+(aq) + 2 Cl-(aq) + 2 Ag+(aq) + 2 NO3-(aq) → Ca2+(aq) + 2 NO3-(aq) + 2 AgCl(s)
In the above ionic equation, the Ca2+ and the NO3- ions appear on both sides of the equation. These ions are similar and do not take part in the reaction. They are known as spectator ions. Once, the spectator ions are removed, the resulting equation is a net ionic equation. In this case, the net ionic equation appears as follows:
2 Cl-(aq) + 2 Ag+(aq) → 2 AgCl(s)