Here's how to write the complete ionic equation for the reaction between copper(II) sulfate and barium chloride:

1. Write the balanced molecular equation:

CuSO₄(aq) + BaCl₂(aq) → CuCl₂(aq) + BaSO₄(s)

2. Identify the soluble ionic compounds and break them down into their ions:

* CuSO₄(aq) → Cu²⁺(aq) + SO₄²⁻(aq)

* BaCl₂(aq) → Ba²⁺(aq) + 2Cl⁻(aq)

* CuCl₂(aq) → Cu²⁺(aq) + 2Cl⁻(aq)

3. Note that BaSO₄ is insoluble and remains as a solid:

* BaSO₄(s) → BaSO₄(s)

4. Combine the ions from the soluble compounds and the solid:

Cu²⁺(aq) + SO₄²⁻(aq) + Ba²⁺(aq) + 2Cl⁻(aq) → Cu²⁺(aq) + 2Cl⁻(aq) + BaSO₄(s)

This is the complete ionic equation.

Key points:

* The complete ionic equation shows all the ions present in the solution, both before and after the reaction.

* The insoluble solid (precipitate) remains as a single unit in the equation.

* The spectator ions, which appear on both sides of the equation, are not involved in the net ionic equation.