Answer:
ZnS(s) ⇄ S²⁻(aq) + Zn²⁺(aq)
Explanation:
First, we will write the molecular equation, since it is easier to balance.
2 HBr(aq) + ZnS(s) ⇄ H₂S(aq) + ZnBr₂(aq)
In the full ionic equation we include all ions and molecular species.
2 H⁺(aq) + 2 Br⁻(aq) + ZnS(s) ⇄ 2 H⁺(aq) + S²⁻(aq) + Zn²⁺(aq) + 2 Br⁻(aq)
In the net ionic equation we include only the ions that participate in the reaction and the molecular species.
ZnS(s) ⇄ S²⁻(aq) + Zn²⁺(aq)
Lower the pH because increased number of free hydrogen ions
