A set ionic equation, also known as a complete ionic equation, is a chemical equation that shows all the ions present in a reaction. It represents the dissociation of all soluble compounds into their respective ions. This type of equation is commonly used to describe reactions that occur in aqueous solutions.
To write a set ionic equation, you follow these steps:
1. Write the balanced molecular equation for the reaction.
2. Dissociate any soluble compounds into their respective ions.
3. Write each ion separately, indicating their charges.
4. Include state symbols (s, l, g, or aq) for each substance, indicating whether it is a solid, liquid, gas, or aqueous solution.
For example, let's consider the reaction between sodium chloride (NaCl) and silver nitrate (AgNO3):
NaCl(aq) + AgNO3(aq) -> AgCl(s) + NaNO3(aq)
To write the set ionic equation, we first need to dissociate the compounds that are soluble:
Na+(aq) + Cl-(aq) + Ag+(aq) + NO3-(aq) -> AgCl(s) + Na+(aq) + NO3-(aq)
In this equation, the sodium ions (Na+) and nitrate ions (NO3-) remain the same on both sides of the equation, so they are called spectator ions. The silver ions (Ag+) and chloride ions (Cl-) are involved in the formation of the precipitate (AgCl) and are considered the main players in the reaction.
I hope this helps! Let me know if you have any other questions.