Net ionic equation

A net ionic equation is a chemical equation that only shows the species that are directly involved in a chemical reaction, excluding spectator ions that do not participate in the reaction. This allows for a clearer representation of the actual chemical changes that occur during a reaction.

For example, in the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) to form water (H2O) and sodium chloride (NaCl), the complete ionic equation is:

HCl(aq) + NaOH(aq) -> H2O(l) + NaCl(aq)

The net ionic equation for this reaction would be:

H+(aq) + OH-(aq) -> H2O(l)

This net ionic equation shows that the hydrogen ion (H+) from the acid reacts with the hydroxide ion (OH-) from the base to form water.

Net Ionic Equation

A net ionic equation is a chemical equation that shows only the ions that are actually reacting. Spectator ions, which are ions that do not participate in the reaction, are omitted.

Steps to Write a Net Ionic Equation:

1. Write the balanced equation for the reaction.
2. Identify the spectator ions. Spectator ions are ions that appear on both sides of the equation and do not undergo any changes.
3. Remove the spectator ions from the equation.
4. Balance the remaining equation.
5. Add water molecules (H₂O) to balance the hydrogen and oxygen atoms.
6. Simplify the equation.

Example:

Balanced Equation:

```
2Na₂CO₃(aq) + CaCl₂(aq) → Na₂Ca(CO₃)₂(s) + 2NaCl(aq)
```

Spectator Ions:

- Na⁺ and Cl⁻

Net Ionic Equation:

```
Ca²⁺(aq) + CO₃²⁻(aq) → CaCO₃(s)
```

Note:

- The net ionic equation shows that the actual reaction occurs between the calcium (Ca²⁺) and carbonate (CO₃²⁻) ions.
- The arrow in the net ionic equation indicates the direction of the reaction.
- Net ionic equations are useful for understanding the fundamental chemical changes that occur in a reaction.