Answer:
- Exothermic; lower
Explanation:
First let's determine whether the dissolution of PrF₂ is endo or exo thermic.
This indicates that as temperature increases, the rate of the forward reaction decreases meaning that this reaction is exothermic.
Since the reaction is exothermic and the dissolution value is higher at lower temperatures, the dissolution process occurs at lower termperatures.
Therefore, the correct answer is Exothermic; lower.