Match the List - I with List - II
`{:(,"List - I",,"List - II"),((P),"van Arkel method",(1),"Purification of copper"),((Q),"Poling",(2),"Refining of silver"),((R),"Cupellation",(3),"Manufacture of "Na_(2)CO_(3)),((S),"Solvay process",(4),"Purification of titanium"):}`

Options

A. `{:(P,Q,R,S),(4,1,3,2):}`
B. `{:(P,Q,R,S),(2,3,1,4):}`
C. `{:(P,Q,R,S),(2,3,4,1):}`
D. `{:(P,Q,R,S),(4,1,2,3):}`

Answer

To solve the matching question between List - I and List - II, we need to analyze each method in List - I and determine which purification or refining process in List - II corresponds to it.

### Step-by-Step Solution:

1. **Identify the van Arkel method**:
- The van Arkel method is also known as vapor phase refining.
- It is primarily used for the purification of titanium.
- **Match**: P (van Arkel method) → 4 (Purification of titanium).

2. **Identify Poling**:
- Poling is a method used for the purification of metals, specifically copper.
- It involves the removal of impurities from molten copper by using a pole made of green wood.
- **Match**: Q (Poling) → 1 (Purification of copper).

3. **Identify Cupellation**:
- Cupellation is a refining process that is used to separate noble metals like silver and gold from their ores.
- It involves heating the ores at high temperatures to extract pure metals.
- **Match**: R (Cupellation) → 2 (Refining of silver).

4. **Identify the Solvay process**:
- The Solvay process is an industrial method for producing sodium carbonate (Na2CO3).
- It involves the reaction of sodium chloride, ammonia, and carbon dioxide.
- **Match**: S (Solvay process) → 3 (Manufacture of Na2CO3).

### Final Matches:
- P → 4 (Purification of titanium)
- Q → 1 (Purification of copper)
- R → 2 (Refining of silver)
- S → 3 (Manufacture of Na2CO3)

### Answer:
The correct matches are:
- P - 4
- Q - 1
- R - 2
- S - 3

Thus, the final answer is option D:
- P → 4
- Q → 1
- R → 2
- S → 3