Question

Enter the net ionic equation for the reaction that occurs when aqueous hydroiodic acid and aqueous strontium sulfide are mixed.

Express your answer as a net ionic equation. Identify all of the phases in your answer.

Answer 1

When hydroiodic acid (HI) and aqueous strontium sulfide (SrS) are mixed, we produce strontium iodide (SrI₂) which is soluble and hydrosulfuric acid H₂S is released as a gas:

HI(aq) + SrS(aq) SrI₂(aq) + H₂S(g)

To balance the above equation place a 2 next to HI so we have 2I and 2H on each side of the equation:

2HI(aq) + SrS(aq) SrI₂(aq) + H₂S(g)

Separate the substances in aqueous solution (aq) of the reaction into ions:

2H⁺ + 2I^- + Sr²⁺ + S^2-  2I^- + Sr²⁺ + H₂S(g)

To get the net-ionic equation, eliminate the terms that appear on both sides:

2H⁺ + S^2- H₂S(g)