When hydrogen sulfide gas (H₂S) is bubbled through a solution of iron(III) chloride (FeCl₃), a precipitation reaction occurs, producing a black precipitate of iron(III) sulfide (Fe₂S₃) and hydrochloric acid (HCl).

Here's the balanced chemical equation:

2 FeCl₃ (aq) + 3 H₂S (g) → Fe₂S₃ (s) + 6 HCl (aq)

Explanation:

* Iron(III) chloride (FeCl₃) is a soluble ionic compound, meaning it dissolves in water to form Fe³⁺ and Cl⁻ ions.

* Hydrogen sulfide (H₂S) is a gas that dissolves in water to form H⁺ and HS⁻ ions.

* Iron(III) sulfide (Fe₂S₃) is an insoluble ionic compound, meaning it does not dissolve in water and forms a solid precipitate.

* Hydrochloric acid (HCl) is a strong acid that remains dissolved in the solution.

The reaction occurs because the sulfide ions (S²⁻) from the dissolved H₂S react with the iron(III) ions (Fe³⁺) to form the insoluble iron(III) sulfide precipitate. This reaction is driven by the formation of the solid precipitate, removing iron(III) ions from the solution and shifting the equilibrium towards product formation.