Question

Explain the following by giving examples.
Sedimentation and Decantation.

Answer 1

Hint:Sedimentation and decantation are the processes of Separation of two compounds such as solid-liquid and liquid-liquid. By these processes we can purify any substance and remove impurities from them. In sedimentation impurities settle down in the bottom of the vessel.


Complete solution:
Sedimentation: The process by which we can separate a solid from a liquid,
 In sedimentation solid particles have a tendency to settle down on the bottom due to higher gravity.
These solid particles can be impurity, ore or any other thing
Example: In a tank we fill impure water and leave it in rest for 6 to 8 hours,
Then the solid impurity settles down in the bottom of the tank and clear water floats above it, we remove clear water with the help of a pump.
Hence, water and impurity are separated.
Sedimentation removes 70-75% impurity from liquid.
Decantation: Decantation is the process by which we can separate two or more immiscible liquids from a mixture, if we want to remove liquid impurities from a liquid solution then we will use a decantation process.
In decantation, in the mixture of two liquids one liquid will have higher density it will go to the bottom of the vessel and another one will float above it.
Example: The mixture of water and oil can be separated by a decantation process when the mixture of water and oil is present in a vessel; a layer between two phases is formed in which oil floats on the top of the water layer.
 We can separate these by pouring top phase in another vessel.


Note:Generally sedimentation is used to clear the dirty water sedimentation is widely used in the Industrial area. There are many methods to separate two or more phases such as distillation, evaporation and titration.