Here's how to write the net ionic equation for the reaction between copper(II) chloride (CuCl₂) and ammonium phosphate ((NH₄)₃PO₄):

1. Write the balanced molecular equation:

3CuCl₂(aq) + 2(NH₄)₃PO₄(aq) → Cu₃(PO₄)₂(s) + 6NH₄Cl(aq)

2. Write the complete ionic equation:

This involves breaking down all soluble ionic compounds into their respective ions:

3Cu²⁺(aq) + 6Cl⁻(aq) + 6NH₄⁺(aq) + 2PO₄³⁻(aq) → Cu₃(PO₄)₂(s) + 6NH₄⁺(aq) + 6Cl⁻(aq)

3. Identify and cancel spectator ions:

Spectator ions are ions that appear on both sides of the equation and do not participate in the reaction. In this case, NH₄⁺ and Cl⁻ are spectator ions.

4. Write the net ionic equation:

The net ionic equation shows only the ions that participate in the reaction:

3Cu²⁺(aq) + 2PO₄³⁻(aq) → Cu₃(PO₄)₂(s)