Anthracene is purified by :

Options

A. Filtraction
B. Crystallisation
C. Distillation
D. Sublimation

Explanation

**Step-by-Step Solution:**

1. **Understanding Anthracene**: Anthracene is a polycyclic aromatic hydrocarbon consisting of three fused benzene rings. It is a solid at room temperature and is often used in the production of dyes and as a precursor to other chemicals.

2. **Purification Techniques**: There are several methods for purifying substances, including sublimation, distillation, crystallization, and fractional distillation. Each method has its specific application based on the physical properties of the substance being purified.

3. **Sublimation Process**: Sublimation is a process where a solid transitions directly into a gas without passing through the liquid phase. When anthracene is heated, it sublimates, meaning it can be converted into vapor and then condensed back into a solid, effectively removing impurities.

4. **Why Other Methods are Not Suitable**:
- **Distillation**: This method is used for separating liquids based on their boiling points. Since anthracene is a solid, distillation is not applicable.
- **Crystallization**: This technique is used to purify solids that have impurities that can be dissolved in a solvent. Anthracene does not fit this method as it does not require a solvent for purification.
- **Fractional Distillation**: This method is used for separating components of a mixture based on their boiling points, similar to distillation, and is not suitable for solid purification.

5. **Conclusion**: The most effective method for purifying anthracene is simple sublimation, as it allows for the direct conversion of the solid to vapor, leaving impurities behind.

**Final Answer**: Anthracene is purified by simple sublimation.

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