Match the characteristics mentioned in Column II with the process in Column I.
`{:(,"Column I",,"Column II"),((A),LiF_((s))+AquararrLiF_((aq)),(p),"Exothermic"),((B),KF_((s))+AquararrKF_((aq)),(q),"Endothermic"),((C),O_((g))+e^(-)rarrO_((g))^(-),(r),"Positive affinity"),((D),O_((g))^(-)+e^(-)rarrO_((g))^(2-),(s),"Negative affinity"):}`

Explanation

To solve the problem of matching the characteristics in Column II with the processes in Column I, we will analyze each process and determine the corresponding characteristic based on the principles of thermodynamics and electron affinity.

### Step-by-Step Solution:

1. **Process A: LiF(s) + H2O → LiF(aq)**
- When solid lithium fluoride (LiF) dissolves in water, it forms aqueous lithium fluoride.
- The process involves hydration energy, which is the energy released when ions are surrounded by water molecules.
- Since the hydration energy is greater than the lattice energy (energy required to separate the ions in the solid), this reaction is **exothermic**.
- **Match:** A → P (Exothermic)

2. **Process B: KF(s) + H2O → KF(aq)**
- Similar to LiF, solid potassium fluoride (KF) dissolves in water to form aqueous KF.
- However, in this case, the hydration energy is less than the lattice energy. Therefore, energy must be supplied for the dissolution to occur, making this process **endothermic**.
- **Match:** B → Q (Endothermic)

3. **Process C: O(g) + e⁻ → O⁻(g)**
- This process involves the addition of an electron to a neutral oxygen atom to form an oxide ion (O⁻).
- The energy change associated with this process is known as electron affinity. For oxygen, this process releases energy, indicating a **positive affinity**.
- **Match:** C → R (Positive affinity)

4. **Process D: O⁻(g) + e⁻ → O²⁻(g)**
- In this case, we are adding another electron to the already negatively charged oxide ion (O⁻) to form a doubly charged oxide ion (O²⁻).
- This process requires energy because of the electron-electron repulsion (two negatively charged species repel each other), indicating a **negative affinity**.
- **Match:** D → S (Negative affinity)

### Final Matches:
- A → P (Exothermic)
- B → Q (Endothermic)
- C → R (Positive affinity)
- D → S (Negative affinity)