Question

Which one of the following methods can be used to obtain highly pure metal which is liquid at room temperature?

• A. Zone refining
• B. Electrolysis
• C. Chromatography
• D. Distillation

Answer 1

The Correct Option is D

To determine which method is suitable for obtaining highly pure metal that is liquid at room temperature, we need to analyze the properties and applicability of each method listed:

1. Zone Refining:

   This method is useful for the purification of semiconductors and metals that have high melting points. It involves heating a narrow region of the material to a temperature that allows the impure elements to dissolve and migrate, ultimately producing a highly pure crystal. However, this method is not ideal for metals that are liquid at room temperature.

2. Electrolysis:

   Electrolysis involves passing an electric current through a solution containing the metal, which causes the metal to deposit in pure form. While effective for metals in ionic form, it is not practical for metals that are innately liquid at room temperature.

3. Chromatography:

   This technique is used for separating mixtures based on the differential partitioning between stationary and mobile phases. It is unsuitable for purifying metals, especially those liquid at room temperature, due to the need for a separation medium and specific phases.

4. Distillation:

   This method is ideal for separating substances based on differences in volatility. Metals that are liquid at room temperature, such as mercury, can be purified effectively using distillation since it separates the metal based on its relatively low boiling point compared to impurities. This makes it the best choice for purifying metals in a liquid state at room temperature.

Therefore, the correct answer is Distillation. It is the most appropriate method for purifying metals that are liquid at room temperature, such as mercury, due to its ability to exploit differences in boiling points.