Separation Techniques

Fractional distillation is a technique to separate a mixture of liquids on the basis of the difference in their boiling points. During heating, one and more fraction(s) of the mixture will vapourise.

Chromatography is a method in which sample extract being dissolved in a mobile phase. The mobile phase is then forced through an immobile, immiscible stationary phase. The phases are chosen such that components of the sample have differing solubilities in each phase. A component which is quite soluble in the stationary phase will take longer to travel through it than a component which is not very soluble in the stationary phase, but very soluble in the mobile phase. As a result of these differences in mobilities, sample components will become separated from each other as they travel through the stationary phase. 

Bar magnet is used to separate sand from iron filings.

Immiscible liquids are separated by a separating funnel.

Denser particles are forced to the bottom and lighter particles stay at the top when spun rapidly irrespective of the direction of the rotation.

Infiltration happens when water soaks into the soil from the ground level. It moves underground and moves between the soil and rocks. Some of the water will be soaked up by roots to help plants grow.

Fractional distillation is used for separating liquids which differ in their boiling points by 20°C or more.

Natural gas liquids (NGLs) are separated from methane using absorption processes, cryogenic expansion (cooling to liquefy heavier components), and fractionation towers. Magnetic processes have no application in gas-liquid separation as these methods don't differentiate based on magnetic properties in this context.

We use the method of filtration to separate the tea leaves from the prepared tea. The tea strainer is held in the hand while pouring the tea in the cup. The liquid tea is poured into the cup, and the tea leaves remain in the strainer. This method is called filtration. 

The harmful substances from rice like stones and insects are separated from picking by hand. The stones and insects are picked by hand and then separated from it. 

Sieving is a method of separation, which is used at construction sites. In this process, the stones or pebbles are separated from sand by sieving. Sand is needed at construction sites for construction like buildings, temples etc.

Shallow vessel with small holes at its bottom is used in sieving. A sieve is a shallow vessel with small holes at its bottom, and hence the method of separating the components of a mixture that are of different sizes is called sieving.

Kerosene oil and water can be separated by the process of decantation by using a separating funnel. Kerosene oil does not dissolve in water and forms a seperate layer. As kerosene is lighter, it would remain in the separating funnel and water being heavier would fall down in the beaker.

Sand is separated from water in sedimentation. When sand settles down at the bottom of the beaker and the clear water is left above the layer of sand, it is known as sedimentation.

Separating grains from the rest of the plant is an example of threshing, not filtration.