Sodium sulfite (Na₂SO₃) is a soluble salt that completely dissociates in water. Here's how to write the net ionic equation:

1. Write the dissociation equation:

Na₂SO₃(aq) → 2Na⁺(aq) + SO₃²⁻(aq)

2. Identify the spectator ions:

Spectator ions are ions that appear on both sides of the equation and do not participate in the reaction. In this case, the spectator ion is Na⁺.

3. Remove the spectator ions:

Since sodium sulfite is a soluble salt, it simply dissolves in water and does not undergo any further reaction. This means there is no net ionic equation.

Therefore, the net ionic equation for a solution of sodium sulfite is: There is no net ionic equation.