Separation of Substances

In our daily life we separate substance from the mixture. But did you even notice that how you are separating it and which methods are you using to separate the substance. We will discuss about it but firstly you know what is the meaning of Separation of substance.

Process of removing one or more components from a mixture is known as Separation. For example grains are separated from stalk while harvesting, milk or curd is churned to separate butter, tea leaves are separated from the liquid with a strainer while preparing tea etc.

Purpose for separation of Substance

For removing unwanted particles

•  You have seen in your house that your mother removes stones from rice before she cooks. Because stones are very             harmful and unwanted substance for our body. So, removing of stones from rice is very necessary.
• We also see that our mother removes tea leaves from a tea using strainer so that one can drink it. Thus, tea leaves are to be separated.
• Fruit custard is the mixture of many fruits like mango, strawberry, banana, apple, cherry etc. But if someone doesn’t like mangos because he/she is having allergy than we will separate mangos to avoid reaction. So, separation of unwanted particles is necessary.
• Even water which we drink daily is been purified as many dust particles are their in it. So this particles doesn’t harm separation is necessary.

For getting important substance

• Saltwater is not at all important for us but individually salt and water are important.  Thus separation of saltwater is necessary to get salt and water which we can use.
• We all eat butter. Butter is made from milk. Milk is churned at high speed which create a froth up. This froth up is called butter. And thus butter is separated from milk.
• Crude oil is a raw oil. It means it is a mixture of many other oils like diesel, kerosene, petrol, etc. As many oil are mixed together crude oil not used. Thus crude oil is separated into other oil which can be used individually.

Now we understood the purpose and meaning of separation. But what are the methods to be used to separate substances.

Methods of Separation

Handpicking, winnowing, sieving, sedimentation, decantation and filtration are some of the methods of separating substances from their mixtures.

Let us study about this methods in detail

Handpicking

• Handpicking is a separation method which is used to remove unwanted substance from a mixture using hands.
• For example, removing of stones from rice, wheat etc using hands.
• This is very simple method. By picking unwanted substance from mixture by hand and separating them from others.
• Handpicking method can be used when the items are different on the basis of their color, shape and weight.

Winnowing

• Winnowing is a separation method in which heavy substance are separated from lighter substance with the help of wind.
• Mostly this method is used to remove husk from grains after the method of threshing.
• Threshing is the process of separating grains from chaff.
• For example, dirt particles can be removed from grains by winnowing, corn are separated from straw by winnowing.

Sieving

• Sieving is the simple method of separating substance on the basis of their sizes.
• This method is used in a flour mill where impurities like husk and stones are removed from wheat before grinding it.
• For example, in a flour mill, impurities like husk and stones are removed from wheat before grinding it.

Sedimentation

• Sedimentation method is used to separate solid substance from liquid substance.
• Sedimentation principle. In a solution, particles whose density is higher than that of the solvent sink and particles that are lighter than it float to the top. The greater the difference in density, the faster they move.
• For example, Water treatment plants use the method of sedimentation to filter out unwanted particles from unclean water.

Decantation

• Decantation is the process where liquid can be separated from other liquid of different density.
• For example to separate oil and water, to separate oil and vinegar etc.

Filtration

• Filtration is a process of separating compounds from a solid or liquid mixture is called filtration.
• One of the most common types of filtration equipment used in laboratories is a Buchner funnel.
• Very common example is to separate tea leaves from tea to make it drinkable. To separate sand and water using filtration method.
• This method is slow comparatively to others.

So now after learning this different methods of separating substance, you can also try some activities at your home like :-

1. Take some sand and mix it with water and by using sedimentation method separate them.
2. Make tea and separate tea leaves from tea using filtration method.
3. Take some mixed rice and separate them .

This activities will help you to understand more and your concepts will be more clear.