Here's how to write the balanced complete ionic equation for the reaction between sodium carbonate (Na₂CO₃) and copper(II) nitrate (Cu(NO₃)₂):

1. Write the unbalanced molecular equation:

Na₂CO₃(aq) + Cu(NO₃)₂(aq) → CuCO₃(s) + 2NaNO₃(aq)

2. Identify the soluble and insoluble compounds:

* Soluble: Na₂CO₃, Cu(NO₃)₂, and NaNO₃ (most nitrates and sodium salts are soluble)

* Insoluble: CuCO₃ (most carbonates are insoluble)

3. Break down the soluble compounds into their ions:

2Na⁺(aq) + CO₃²⁻(aq) + Cu²⁺(aq) + 2NO₃⁻(aq) → CuCO₃(s) + 2Na⁺(aq) + 2NO₃⁻(aq)

4. Cancel out spectator ions (ions that appear on both sides of the equation):

2Na⁺(aq) + CO₃²⁻(aq) + Cu²⁺(aq) + 2NO₃⁻(aq) → CuCO₃(s) + 2Na⁺(aq) + 2NO₃⁻(aq)

The Balanced Complete Ionic Equation:

CO₃²⁻(aq) + Cu²⁺(aq) → CuCO₃(s)