Answer:
S²⁻(aq) + Cu²⁺(aq) ⇒ CuS(s)
Explanation:
Let's consider the molecular equation that occurs when aqueous solutions of lithium sulfide and copper (II) nitrate are mixed.
Li₂S(aq) + Cu(NO₃)₂(aq) ⇒ 2 LiNO₃(aq) + CuS(s)
The complete ionic equation includes all the ions and the species that do not dissociate in water.
2 Li⁺(aq) + S²⁻(aq) + Cu²⁺(aq) + 2 NO₃⁻(aq) ⇒ 2 Li⁺(aq) + 2 NO₃⁻(aq) + CuS(s)
The net ionic equation includes only the ions that participate in the reaction and the species that do not dissociate in water.
S²⁻(aq) + Cu²⁺(aq) ⇒ CuS(s)