Separating Components of Mixture
If some substances are mixed by mistake, then they need to be separated from each other, but sometimes it is very difficult to separate them. In such situations we use a variety of special methods, such as filtering, gleaning, sublimation, evaporation, precipitation to easily separate substances.
1. Gleaning (Handpicking)
You must have noticed that in homes, often grains and pulses are picked by hand by separating the pebbles. This method is called gleaning. This can happen because the color, shape, grain, and pulses of the substances found in the mixture differ from the particles in the mixture.
How to clean wheat, rice in the house? They are winnowed and cleaned. In wheat, pebbles - stones, straw are separated by winnowing through flail.
When the wheat crop is ready in the field and the straw has to be separated from the wheat, the farmers take the mixture of wheat and straw in the soup and throw it from the height. By doing this, the straw, which is lighter, flies away with the wind and collects it, and the wheat falls down due to the heaviness, which is later cleaned. This is how wheat and chaff are separated.
At home, the mother uses a sieve to separate the bran (husk) from the flour. The sieve separates those substances which have different sizes of particles. Sand and scree are also separated in a similar way.
4. By Magnet
When a substance is found in the mixture, which can be attracted towards the magnet, it can be separated by the magnet. If iron shavings are found in the sawdust, it can be separated in this way.
When we put a naphthalene ball in woolen clothes, it gradually disappears. This happened because some solid matter becomes vapor without changing into liquid.
Have you ever noticed camphor burning in worships, it is also an example of this. If one of the substances inside the mixture is such a solid that it becomes vapor without changing into liquid, then by this method, it is separated from the mixture.
We use the evaporation method to obtain salt from sea water. For this, we fill the water in a pit and due to the sunlight, the water gradually evaporates and the salt remains in the pit. You can heat the solution to get salt from the salt solution in the house and can get salt by blowing water from it.
Sand and water solutions are easily separated by the filtration method. Putting filter paper in the funnel, the sand and water solution are gently poured into the funnel. The water is filtered and goes into the beaker and the sand remains on top.
8. Sedimentation and Decantation
If you make a solution of sand and water and leave it in a beaker, you will see that the sand settles down slowly. The sand gets sediment. This is called sedimentation. The water comes up. Pour out the water and separate it.
When the above clean water is poured into another vessel, this process is called Decantation.
Take the dirty water and keep it for a while. See what happens? Does the dirt sit down slowly? Yes, but with a little shaking, dirt particles start appearing again in the water. Now tie the alum in a thread and hang it in the middle of dirty water and see what happens? The particles of mud along with alum particles get heavy and sit in the bottom, that is, they become depressed, which are then removed and separated. This method is called loading.
Distilled water is required to make medicines. Distilled water is also needed for research in laboratories. Distilled water is obtained by distillation method. In this, the water is first heated and steam is made, which is collected and cooled and we get distilled water.