Distillation

Definition:
Distillation is a method of separating a mixture of liquids based on the differences in their boiling points. It involves heating the mixture to convert the liquid with the lower boiling point into vapor and then cooling the vapor to obtain the pure liquid.

Process of Separating Common Salt from Sea-water:
The separation of common salt (sodium chloride) from sea-water can be achieved through the process of distillation. Here is a step-by-step explanation of the process:

1. Collection of Sea-water: Sea-water is collected from the ocean or any other source of saltwater.

2. Heating the Sea-water: The collected sea-water is heated in a container or a distillation apparatus. As the temperature rises, the water molecules start to gain energy and convert into vapor.

3. Condensation: The vapor that is produced during heating is then passed into a condenser. The condenser cools down the vapor, causing it to condense back into liquid form.

4. Separation of Salt: As the vapor condenses, it becomes pure water, free from impurities such as salt. The salt, being a solid, remains behind in the original container or distillation apparatus.

5. Collection of Distilled Water: The pure water, which is now separated from the salt, is collected in a separate container. This water is free from impurities and can be used for various purposes.

6. Collection of Salt: The salt that remains in the original container or distillation apparatus can be collected separately. It can be further processed through the method of crystallization to obtain pure salt crystals.

Advantages of Distillation:
- Distillation allows the separation of substances based on their boiling points, making it an effective method for separating liquids from a mixture.
- It can be used to obtain pure water from impure sources such as sea-water, where the salt content is high.
- The process is relatively simple and can be carried out on a large scale for commercial purposes.

Disadvantages of Distillation:
- Distillation requires a significant amount of energy for heating the mixture, which can be expensive.
- It is a time-consuming process, especially when separating large quantities of liquids.
- Some substances may decompose or change their properties at high temperatures, limiting the applicability of distillation in certain cases.