Final answer:
The correct net ionic equation for the reaction between potassium iodide and cobalt(II) sulfate is 2I−(aq) + Co−∛(aq) → CoI₂₋(s), which represents the reaction of iodide ions with cobalt(II) ions to form cobalt(II) iodide.
Step-by-step explanation:
When potassium iodide (KI) reacts with cobalt(II) sulfate (CoSO4), the net ionic equation can be determined by removing the spectator ions. In the options provided, potassium (K+) and sulfate (SO42−) ions are the spectators, as they do not participate in the actual reaction and stay in solution. This means that the correct net ionic equation will only include the ions that form a precipitate or undergo a change. For instance, in the example reaction of lead(II) nitrate with potassium iodide, Pb2+ and I− ions combine to form a precipitate of lead iodide (PbI2), which is insoluble. Applying similar principles to the reaction between KI and CoSO4, the cobalt(II) ions (Co2+) react with iodide ions (I−) to form cobalt(II) iodide (CoI2), which is the product of interest. Therefore, the correct net ionic equation is:
2I−(aq) + Co2+(aq) → CoI2(s)
This equation indicates that cobalt(II) ions and iodide ions react to form solid cobalt(II) iodide while potassium and sulfate ions remain in solution as spectator ions. It is important to ensure that both mass and charge are conserved in the net ionic equation.