In the previous chapter 4 of class 6 science, we studied about shorting materials into groups according to their properties and nature of materials. In this chapter, separation of substances class 6 notes, we will study the separation of substances from a mixture or solution. In our daily lives, we separate many substances from a mixer, like stones from pulses and rice. In scientific terms, this process of separation is called handpicking separation.

Methods of Separation:

There are many types of separation processes, which are discussed below by our team. Let’s discuss the different processes of separation:

Handpicking: –

In this process, the separation of substances from a mixture or solution is done by hand. For example, separation of stone or similar substance from pules or rice by our hand. This is an example of handpicking separation. The handpicking method is used for the separation slightly large mixtures.

Threshing: –

We will try to understand this method by an example. We see many agricultural lands around us. After crop harvesting, the crop will dry in sunlight. Then a lot of grains are present in one single plant of crop. This is very difficult to separate the grains from the crop. So that why to separate the grain we will beat the bundle of crop plant by stone or any hard thing to remove the grains from plants. This process of separation of grains from crop plant bundles is called threshing. Bullock and machines are also used for threshing.

Winnowing: –

Winnowing is the process of separating heavier and lighter weight mixtures.  This process is also easy to understand by an example. From the example of threshing, after threshing we collet the grains in a plate. Then, if we see carefully, there are some dust and dry leaves present in the grains. Now the question is, how can we separate from it? Turn on the wind blower (not the roof fan) and pick the plate that contains the grain and dust mixture above the height of our body. Now put slowly the mixture in front of the wind, then we notice the grains are put down and dust and leaves are thrown away from the grains. All the process is called winnowing.

Sieving: –

This method is used to separate the substances by using a sieve or any material like a sieve. For example, if we want to make any dish from flour, Then we use a sieve and pour the flour. Then we see the flour pass through it, and some small impurities are not passed. This process is called sieving.

Sieving is used only when a mixture is made from different-sized substances.

The above methods are usually used for large-size mixture substance separation. Now in this chapter we will discuss how we can separate small or micro sized substances and how we can separate the solutions. There are three major methods for using small or micro sized substances and solutions. Let’s discuss:

Sedimentation: –

When the mixture is made from the same size substance or a small or micro size substance that is not able to be separated by easy method. Then, if we add water to the mixture, after adding water, the heavier nature substance gets down after some time of adding water. This complete process is called sedimentation. For example, take some rice with dust or dry leaves. Now it is too hard to remove the dust completely by hand; we have to add some water to this mixture. After adding water, rice gets down in the pot, and dust will not get down. This process of separation is called sedimentation.

Decantation: –

After the complete process of sedimentation, the removal of water with impurities is called decantation.

Filtration: –

Let’s understand this method by giving examples. When we make tea, we have to separate tea leaf from tea. By using sedimentation and decantation, can we separate completely? The answer is no. For complete separation, we have to pour it. For pour, we use a stainer, and the separation is complete. This complete process is called filtration.

Passes the solution mixture from a substance that has small/micro/nano holes for separation is called filtration.

Evaporation: –

The process of converting water into vapor is called evaporation. This process is also used for separation. Let’s take an example: some substances are soluble. Take a spoon slat and put it in a glass of water and shake well. Now slat completely dissolves into water. Now the task is: how can we separate salt from water? Heat the water solution until it converts into vapors. After some time, we notice a layer of white substance will be made on the edge of the beaker. When water gets completely into vapor. Only white substances will remain in the beaker.

Use more than one method for separation: –

In this chapter we study different methods of separation. But some mixtures are not separated by a single method; they require two or more methods to separate. Take a mixture of sand and salt. How can we separate it?

Take a beaker and put this mixture in it, and add a glass of water to it. After shaking this solution, we notice sand will get down to the bottom of the beaker, but salt will dissolve in water. Getting down sand is sedimentation. Now the salt and water solution separate from sand. This process is called decantation. Now we try to separate salt and water. Heat the water until it changes into vapors. After changing into vapors, we notice only salt will remain in the beaker. This process is called evaporation. For vapor change into water, we can use an ice plate above the beaker when we heat the salt and water solution. Vapor changes into water; this complete process is called condensation.

So, this is an example of using more than one method for separating a mixture.

Can water dissolve any amount of a substance?

No, this is a certain limit for dissolved in water. You can test in your home or classroom. Every soluble substance has a different dissolving capacity.