Final answer:
To enhance the formation of [FeSCN]2+ in the given reaction, adding additional SCN– or Fe3+ shifts the equilibrium to the right according to Le Chatelier's Principle, thereby increasing the concentration of [FeSCN]2+ and deepening the red color of the solution.
Step-by-step explanation:
To enhance the formation of [FeSCN]2+ in the reaction Fe3+(aq) + SCN–(aq) ⇌ [FeSCN]2+(aq), we could add more SCN– or Fe3+. Adding more SCN– shifts the equilibrium to the right, favoring the formation of [FeSCN]2+ because of the decrease in SCN– concentration due to its consumption in the reaction. Similarly, when more Fe3+ is added, according to Le Chatelier's Principle, the system will react to this change by increasing the rate of the forward reaction, which also shifts the equilibrium to the right, leading to an increase in the concentration of [FeSCN]2+ and a deeper red color in the solution.