Difference Between Molecular Equation and Ionic Equation

The key difference between molecular equation and ionic equation is that the molecular equation shows the reactants and products in molecular form, while the ionic equation shows the ionic species involved in the reaction.

Chemical reactions are interactions between chemical compounds to form new compounds or to rearrange their chemical structure. The compounds that undergo a certain chemical reaction is called a reactant, and what we get at the end is called the product. There are different forms of chemical equations, such as molecular equations and ionic equations. In this article, let’s examine the difference between molecular equation and ionic equation.

1. Overview and Key Difference
2. What is a Molecular Equation
3. What is an Ionic Equation
4. Side by Side Comparison – Molecular Equation vs Ionic Equation in Tabular Form
5. Summary

What is a Molecular Equation?

A molecular equation represents the reactants and products in molecular form. In contrast, an ionic equation gives only the ionic species involved in the chemical reaction. Therefore, in the molecular equation, we should not include any ionic species, only molecules. For example, the reaction between sodium chloride and silver nitrate gives a white precipitate known as silver chloride. The molecular equation for this reaction is as follows:

NaCl + AgNO₃ ⟶ AgCl + NaNO₃

What is an Ionic Equation?

The ionic equation is a way of writing a chemical equation using the ionic species that were involved in the chemical reaction. There are two types of ionic equations as complete ionic equation and net ionic equation. The complete ionic equation is a chemical equation that explains the chemical reaction, clearly indicating the ionic species present in a solution. An ionic species is either an anion (negatively charged species) or a cation (positively charged species). In contrast, a complete molecular equation gives the molecules that take part in a chemical reaction.

The net ionic equation is a chemical equation that shows the ions that participated in the formation of the final product. Further, this equation can be obtained from the complete ionic equation by cancelling out the similar ions from the two sides of the complete ionic equation. Hence, the net ionic equation does not give details about all the ionic species present in the reaction mixture. For the same reaction given above, the ionic equation is as follows:

Na⁺ + Cl^– + Ag⁺ + NO₃^– ⟶ AgCl + Na⁺ + NO₃^–

What is the Difference Between Molecular Equation and Ionic Equation?

Molecular equation and ionic equation are two types of chemical equations we can use to represent chemical reactions. The key difference between molecular equation and ionic equation is that the molecular equation shows the reactants and products in molecular form, while the ionic equation only shows ionic species. Thus, the molecular equation is given in the molecular form, whereas the ionic equation is given in the ionic form. For example, let us look at the reaction between sodium chloride and silver nitrate, which gives a white precipitate known as silver chloride. Its molecular equation is NaCl + AgNO₃ ⟶ AgCl + NaNO₃ while the ionic equation is Na⁺ + Cl^– + Ag⁺ + NO₃^– ⟶ AgCl + Na⁺ + NO₃^–.

Below infographic summarizes the difference between molecular equation and ionic equation.

Summary – Molecular Equation vs Ionic Equation

Molecular equation and ionic equation are two types of chemical equations we can use to represent chemical reactions. As their names suggest, a molecular equation is given in the molecular form, whereas an ionic equation is given in the ionic form. So, the key difference between molecular equation and ionic equation is that molecular equation shows the reactants and products in molecular form, while the ionic equation only shows the ionic species in the reaction.

Reference:

1. Helmenstine, Anne Marie. “Molecular Equation Definition (Chemistry).” ThoughtCo, Jul. 3, 2019, Available here.
2. Helmenstine, Anne Marie. “What Is an Ionic Equation and How Is It Used?.” ThoughtCo, Aug. 1, 2019, Available here.