Absolute alcohols (`100%` ethanol) are prepared from rectified spirit (`95%` ethanol) by mixing a suitable amount of …….. And subjected to fractional distillation (azeotropic distillation).

Options

A. Toluene
B. o-Xylene
C. Methanol
D. Benzene

Explanation

To prepare absolute alcohol (100% ethanol) from rectified spirit (95% ethanol), we follow these steps:

### Step-by-Step Solution:

1. **Understanding Rectified Spirit**: Rectified spirit is a solution that contains approximately 95% ethanol and 5% water along with some impurities. To obtain absolute alcohol, we need to remove the water and any other impurities.

2. **Choosing a Suitable Substance**: To effectively separate ethanol from water and impurities, we can mix a suitable substance that will help in the separation process. In this case, benzene is commonly used.

3. **Mixing Benzene with Rectified Spirit**: Add a suitable amount of benzene to the rectified spirit. The benzene will interact with the water and impurities present in the rectified spirit.

4. **Understanding the Role of Benzene**: When benzene is mixed with the rectified spirit, the water and impurities will preferentially dissolve in the benzene due to its non-polar nature, leaving behind a purer form of ethanol.

5. **Fractional Distillation**: After mixing, the next step is to subject the mixture to fractional distillation. This process utilizes the difference in boiling points between ethanol and benzene to separate them.

6. **Collecting Absolute Alcohol**: During fractional distillation, ethanol, having a lower boiling point than benzene, will vaporize first. The vapors are then condensed back into liquid form, resulting in the collection of nearly pure ethanol (absolute alcohol).

7. **Final Product**: The final product obtained after the distillation process is absolute alcohol, which is 100% ethanol.