Select the incorrect statement ?

Options

A. CO is a better reducing agent thatn C at `673K`.
B. Van Arkel method is a vapour phase refining which is used for refining ziroconium and titanium.
C. Out of C and `CO,CO` is a better reducing agent for ZnO.
D. In extraction of copper matte is put in silica lined converter where self reduction occurs.

Explanation

To solve the question of selecting the incorrect statement, we will analyze each of the provided statements step by step.

### Step 1: Analyze the First Statement
**Statement:** "CO (carbon monoxide) is a better reducing agent than coke (carbon) at 673 Kelvin."

- **Analysis:** Carbon monoxide and coke are both good reducing agents. At 673 Kelvin, carbon monoxide can be easily oxidized to carbon dioxide, while coke can be oxidized to carbon monoxide. Therefore, at this temperature, carbon monoxide is indeed a better reducing agent than coke.

**Conclusion:** This statement is **true**.

### Step 2: Analyze the Second Statement
**Statement:** "Van Arkel method is a vapor phase refining method used for refining zirconium and titanium."

- **Analysis:** The Van Arkel method is indeed a vapor phase refining technique used for refining metals like zirconium and titanium. This method involves the formation of metal iodides, which are then decomposed to yield pure metals.

**Conclusion:** This statement is **true**.

### Step 3: Analyze the Third Statement
**Statement:** "Out of coke and carbon monoxide, carbon monoxide is a better reducing agent for zinc oxide."

- **Analysis:** The reduction of zinc oxide (ZnO) typically occurs at lower temperatures. While carbon monoxide is a good reducing agent, it is more effective at higher temperatures. In contrast, coke (carbon) is more suitable for the reduction of zinc oxide at lower temperatures. Therefore, this statement is incorrect because coke is the better reducing agent for zinc oxide.

**Conclusion:** This statement is **false**.

### Step 4: Analyze the Fourth Statement
**Statement:** "In the extraction of copper metal, metal is put in a silica-lined converter where self-reduction occurs."

- **Analysis:** In the extraction of copper, the process does involve a silica-lined converter where self-reduction of copper occurs. This is a well-known method in metallurgy.

**Conclusion:** This statement is **true**.

### Final Conclusion
After analyzing all the statements, the only incorrect statement is the third one: "Out of coke and carbon monoxide, carbon monoxide is a better reducing agent for zinc oxide."