Separation Techniques: Class 9- Chemistry – CH 2 – Is Matter Around Us Pure

Separation Techniques: Class 9- Chemistry – Chapter 2 – Is Matter Around Us Pure

Separation Techniques

1. Handpicking:

◆This method involves manually picking out components of a mixture based on their visible differences.

◆It’s commonly used when the components have distinct appearances or sizes, making them easy to separate by hand.

◆For example, picking out stones from rice grains or separating different colored candies.

2. Sieving:

◆Sieving is a method used to separate particles based on their size.

◆A sieve, typically a mesh or perforated surface, allows smaller particles to pass through while retaining larger particles.

◆It’s effective for separating solids of different sizes, like separating gravel from sand or flour from larger particles in baking.

3. Filtration:

◆Filtration separates components based on their ability to pass through a filter medium.

◆The mixture is passed through a porous material (filter paper, sand, or cloth), which allows the liquid or smaller particles to pass through while retaining larger particles.

◆It’s commonly used to separate solids from liquids or to remove solid impurities from a liquid, such as separating tea leaves from tea or removing sediment from water.

4. Centrifugation:

◆Centrifugation uses centrifugal force to separate components of a mixture with different densities.

◆The mixture is spun at high speeds in a centrifuge, causing denser particles to move towards the bottom while lighter particles move towards the top.

◆It’s widely used in laboratories for separating suspended solids from liquids (e.g., separating blood components) and in industries like dairy for separating cream from milk.

5. Sublimation:

◆Sublimation is the transition of a substance from solid to gas phase without passing through the liquid phase.

◆It’s used to separate volatile solids from non-volatile solids.

◆For example, separating iodine from a mixture of iodine and sand by heating, where iodine sublimes leaving behind the sand.

6. Chromatography:

 ◆Chromatography separates components based on their differential affinity for a stationary phase and a mobile phase.

◆The mixture is dissolved in a solvent (mobile phase) and passed through a stationary phase.

◆Components with higher affinity for the stationary phase move slower, causing separation.

◆It’s extensively used in analytical chemistry for separating and analyzing complex mixtures like amino acids in proteins or identifying substances in forensic science.

7. Distillation:

◆Distillation separates components based on differences in their boiling points.

◆The mixture is heated to vaporize the more volatile component, which is then condensed back into a liquid and collected.

◆It’s widely used in the production of purified water, alcoholic beverages, and petroleum refining.

8. Crystallization:

◆Crystallization separates solute from solvent by evaporating the solvent, leaving behind the solute as crystals.

◆It’s used to purify substances from impurities or to recover dissolved solids from a solution.

◆Commonly used in the production of salt from seawater or in the pharmaceutical industry to obtain pure crystals of drugs.