Final answer:
The correct net ionic equation for the formation of an aqueous solution of NiI2 accompanied by the evolution of CO2 gas from the reaction of solid NiCO3 and aqueous hydriodic acid is NiCO3 (s) + 2H+ (aq) → H2O (l) + CO2 (g) + Ni2+ (aq).
Step-by-step explanation:
When a solid such as nickel carbonate (NiCO3) reacts with an aqueous solution like hydriodic acid (HI), the products include water (H2O), carbon dioxide (CO2), and nickel iodide (NiI2). The net ionic equation specifically represents the species that actually change during the reaction, excluding the spectator ions that remain unchanged in their ionic form on both sides of the equation.
The given reaction can be depicted as NiCO3 (s) + 2HI (aq) → NiI2 (aq) + H2O (l) + CO2 (g). To arrive at the net ionic equation, we need to consider only the species that actually participate in the reaction. The HI (aq) is strong acid and dissociates completely into H+ and I−.
Considering the reaction products, NiI2 would typically dissociate into Ni2+ and 2I− in an aqueous solution. The net ionic equation excludes the spectator ions (the iodide ions in this case) and only shows the ions and molecules that change. Thus, by removing the spectators, we get option b as the correct net ionic equation: NiCO3 (s) + 2H+ (aq) → H2O (l) + CO2 (g) + Ni2+ (aq).