Final answer:
The reaction Fe³⁺(aq) + SCN⁻(aq) ⇌ FeSCN₂(aq) is endothermic.
Step-by-step explanation:
The reaction Fe³⁺(aq) + SCN⁻(aq) ⇌ FeSCN₂(aq) is endothermic. When a reaction is endothermic, heat is absorbed from the surroundings, causing the temperature to decrease. In this reaction, the forward reaction absorbs heat, resulting in the formation of FeSCN₂(aq).
One way to determine if a reaction is endothermic or exothermic is to look at the direction the reaction shifts to reach equilibrium. In this case, if more Fe³⁺ is added, the equilibrium will shift to the right, producing more FeSCN₂⁺ and causing the solution to become a darker red color. This supports the conclusion that the reaction is endothermic.