In which of the following method of purification metal is converted to its volatile compound which is decomposed to give pure metal?

Options

A. Heating with stream of cabon monoxide
B. Heating with iodine
C. Liquation
D. Distillation

Explanation

To solve the question regarding the method of purification where a metal is converted to its volatile compound which is then decomposed to give pure metal, we can analyze the options provided.

### Step-by-Step Solution:

1. **Understanding the Question**: We need to identify a purification method that involves converting a metal into a volatile compound, which is then decomposed to yield pure metal.

2. **Analyzing the Options**:
- **Option 1: Heating with steam or carbon monoxide**: This method is known as the Mons process. In this process, nickel (for example) is heated with carbon monoxide to form nickel carbonyl (Ni(CO)₄), a volatile compound. Upon heating, this compound decomposes to release pure nickel and carbon monoxide gas. Thus, this option fits the criteria.

- **Option 2: Heating with iodine**: This method is known as the Vann-Arkel process. In this process, zirconium (for example) is heated with iodine to form zirconium iodide (ZrI₄), which is also a volatile compound. When heated further, it decomposes to yield pure zirconium and iodine gas. This option also fits the criteria.

- **Option 3: Liquefaction**: This method generally refers to the process of turning a solid into a liquid, and does not specifically involve the conversion of a metal into a volatile compound.

- **Option 4: Distillation**: This is a separation technique based on differences in boiling points and does not involve the formation of a volatile compound from a metal.

3. **Conclusion**: The correct methods of purification that convert a metal into a volatile compound and then decompose to give pure metal are:
- Heating with carbon monoxide (Mons process)
- Heating with iodine (Vann-Arkel process)

Thus, the answer is **Option 1 and Option 2**.