Assertion :`Ti` can be purified by Van Arkel process.
Reason: `TiI_(4)` is a volatile compound which decomposes at a high temperature.

Options

A. If both (A) and ( R) are correct and ( R) is the correct explanation of (A).
B. If both (A) and ( R) are correct, but ( R) is not the correct explanation of (A).
C. If (A) is correct, but ( R) is incorrect.
D. If (A) is incorrect, but ( R) is correct.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that titanium (Ti) can be purified using the Van Arkel process. This process is known for producing ultra-pure metals, including titanium.

2. **Understanding the Reason**:
- The reason provided is that titanium iodide (TiI₄) is a volatile compound that decomposes at high temperatures. This property is crucial for the Van Arkel process.

3. **Van Arkel Process Overview**:
- The Van Arkel process involves converting the metal into a volatile compound. For titanium, it reacts with iodine to form titanium tetraiodide (TiI₄).

4. **Reaction**:
- The chemical reaction can be represented as:
\[ \text{Ti} + 2 \text{I}_2 \rightarrow \text{TiI}_4 \]
- Here, titanium reacts with iodine to form titanium tetraiodide, which is a volatile compound.

5. **Decomposition of Titanium Iodide**:
- Upon heating, titanium iodide decomposes back into titanium and iodine:
\[ \text{TiI}_4 \xrightarrow{\text{heat}} \text{Ti} + 2 \text{I}_2 \]
- This step leaves behind impurities, allowing for the purification of titanium.

6. **Conclusion**:
- Both the assertion and reason are correct. The assertion that titanium can be purified by the Van Arkel process is valid, and the reason that titanium iodide is a volatile compound that decomposes at high temperature supports this assertion.

7. **Final Answer**:
- Therefore, the correct answer is that both the assertion and reason are correct, and the reason is the correct explanation for the assertion.