Final answer:
The driving force of the given reaction is the formation of a precipitate, specifically the solid nickel sulfide (NiS).
Step-by-step explanation:
The driving force of the reaction Ni(NO₃)₂(aq) + K₂S(aq) → NiS(s) + 2KNO₃(aq) is the formation of a precipitate. In this reaction, NiS (nickel sulfide) is the solid formed, and this precipitation is what drives the reaction forward. Similar reactions where a precipitate is the driving force include situations where a solid silver chloride precipitate forms when NaCl (aq) and AgNO3(aq) react, or the formation of a solid lead iodide precipitate when a lead (II) nitrate solution is mixed with a potassium iodide solution.
The driving force of the reaction Ni(NO₃)₂(aq) + K₂S(aq) → NiS(s) + 2KNO₃(aq) is the formation of a solid. In this reaction, a solid product, NiS, is formed. This can be seen in the balanced chemical equation, where NiS is shown as a product. The other products, 2KNO₃(aq), remain in the form of an aqueous solution.