Question

Which refining process is generally used in the purification of low melting metals ?

• A. Electrolysis
• B. Liquation
• C. Zone refining
• D. Chromatographic method

Hint:

Associate refining methods with specific properties or elements: - \textbf{Low M.P. Metal}: Liquation (e.g., Sn, Pb). - \textbf{Volatile Compound Formation}: Mond process (Ni), van Arkel method (Zr, Ti). - \textbf{High Purity Semiconductors}: Zone Refining (Si, Ge). - \textbf{Reactive Metals/High Purity Cu}: Electrolytic Refining.

Answer 1

The Correct Option is B

The question asks about the refining process used for the purification of low melting metals. Let's consider each option:

1. Electrolysis: This process is commonly used for refining metals like copper and zinc by passing an electric current through an electrolyte solution, separating the pure metal. However, it is not specifically used for low melting metals.
2. Liquation: This is a suitable method for refining metals with low melting points. In this process, the impure metal is heated to a temperature slightly above its melting point. The pure metal melts and flows away from the impurities. Therefore, this technique is particularly effective for low melting metals like tin and lead.
3. Zone Refining: This is used to obtain highly pure metals, especially semiconductors like silicon. A metal rod is passed through a heating coil, allowing impurities to concentrate in a specific zone. It is not specific to low melting point metals.
4. Chromatographic Method: This method involves separating mixture components based on differences in their adsorption on a column. While useful for purification, it is not typically used for metals with low melting points.

Based on the explanation, the refining process that is generally used for the purification of low melting metals is Liquation. The method leverages the lower melting point to separate the pure metal from its impurities effectively.