Question

The method used for the purification of Indium is:

• A. van Arkel method
• B. liquation
• C. zone refining
• D. vapour phase refining

Hint:

Zone refining is the go-to method for producing ultra-pure elements used in the semiconductor industry. Remember key examples: Silicon (Si), Germanium (Ge), Gallium (Ga), and Indium (In).

Answer 1

The Correct Option is C

The method used for the purification of Indium is zone refining.

Let's understand why zone refining is the correct answer and analyze the other options:

1. Zone Refining: This method is based on the principle of fractional crystallization. The process involves moving a small region of the molten metal along a solid rod of the impure metal. As the molten zone passes, it leaves behind purer crystalline metal and carries away impurities. This method is particularly suitable for metals like Indium, which are required in extremely pure states for electronic applications.
2. Van Arkel Method: This is also known as the iodide process and is used for refining metals like Titanium and Zirconium. It involves converting the metal into a volatile compound and then decomposing it to get pure metal. This is not typically used for Indium purification.
3. Liquation: This is a method used to separate metals of different melting points. It is not suitable for the purification of Indium, which requires a high-purity level.
4. Vapour Phase Refining: This method is used for converting the metal into its volatile compound and then decomposing it to revert to pure metal. While this method is effective for some metals, it is not the standard method used for Indium.

In conclusion, zone refining is chosen for Indium primarily because it efficiently removes impurities to achieve the high purity needed for its use in electronic components.