Low melting point metals are purified by:

Options

A. Liquation
B. Zone refinning
C. Chromatography
D. Distillation

Answer

To solve the question regarding the purification of low melting point metals, we will analyze each of the given methods: liquation, zone refining, chromatography, and distillation.

### Step-by-Step Solution:

1. **Understanding Liquation**:
- Liquation is a process specifically designed for the purification of metals with low melting points. In this method, an impure metal is placed in a container that is heated.
- As the temperature rises, the low melting point metal melts and flows down a sloped surface into a collection tub, while the impurities, which have higher melting points, remain solid and do not flow.

2. **Analyzing Zone Refining**:
- Zone refining is a technique used for obtaining high purity metals but is not specifically for low melting point metals.
- This method involves melting a small region of the metal and allowing it to crystallize, which helps in separating impurities. However, it is not suitable for low melting point metals as it requires multiple cycles of melting and crystallization.

3. **Examining Chromatography**:
- Chromatography is primarily a separation technique used for mixtures and solutions, not for purifying metals directly.
- It separates components based on their solubility and interaction with a mobile phase, which is not applicable for solid metals.

4. **Considering Distillation**:
- Distillation is a method used to separate components based on boiling points. For low boiling point metals, this method can be effective.
- However, distillation is not the same as purification of low melting point metals, as it focuses on boiling points rather than melting points.

5. **Conclusion**:
- Based on the analysis, the most suitable method for purifying low melting point metals is **liquation**.
- Therefore, the correct answer to the question is **liquation**.

### Final Answer:
Low melting point metals are purified by **liquation**.