Net Ionic Equation

Lesson: Using solubility rules to write net ionic equation

​By the end of this lesson, you will be able to use solubility rules to write a balanced net ionic equation. ASo, lets learn about solubility rules. Remember that "soluble" means that the substance dissolved in water and "insoluble" means the substance does not dissolve and remains a solid in water.

​Now that you know which ion combination produces an insoluble precipitate, we will use that information to write a net ionic equation. 

What is a net ionic equation?

The net ionic equation is the chemical equation that shows only those elements, compounds, and ions that are directly involved in the chemical reaction.

​For example:
We can write a molecular equation for the formation of silver chloride precipitate as

NaCl_(aq) + AgNO_3(aq) → NaNO_3(aq) + AgCl_(s)

​The corresponding complete ionic equation is:

Na⁺_(aq)+Cl⁻_(aq)+Ag⁺_(aq)+NO₃⁻_(aq)→Na⁺_(aq)+NO₃^-_(aq)+AgCl_(s)

​Notice that I separated the compounds in aqueous, (aq), out into their ions and kept the insoluble precipitate, (s), together.

​If you look carefully at the ionic equation, you will notice that the sodium ion, Na⁺, and the nitrate ion, NO₃^-, appeared unchanged on both sides of the equation. When the two solutions are mixed, neither the Na⁺ nor the NO₃⁻ ions participate in the reaction. They can be eliminated from the reaction.

Na⁺_(aq)+ Cl⁻_(aq)+ Ag⁺_(aq)+ NO₃^-_(aq)→ Na⁺_(aq)+ NO₃^-_(aq)+ AgCl_(s)

A spectator ion is an ion that does not take part in the chemical reaction and is found in solution both before and after the reaction. In the above reaction, the sodium ion and the nitrate ion are both spectator ions.

​The equation can now be written without the spectator ions:

Ag⁺_(aq) + Cl^-_(aq) → AgCl_(s)

Watch this video to see that whol process. As you watch, write down the steps.

​Sometimes, you are only given the reactants and must predict the products. Watch this video on how to predict products.

​Here are some examples. Watch each and note the steps.

​Summary: How to write a balance net ionic equation.

List the steps in writing a net ionic equation.