Separating mixture

1.     Define

·        Metallurgy: The science of extracting metals from their ores is known as metallurgy

·        Pure substance: A pure substance is made of only one kind of particle. For example:Salt is an example of pure substance.

·        Homogenous mixtures: When mixture have uniform composition and we cannot see the two components separately. Such mixtures are known as homogenous mixtures.

·        Heterogenous mixtures: When mixtures do not have uniform compositon and we can see the components of mixture separately. Such mixtures are known as heterogenous mixtures.

·        Filtration: The process of separating fine insoluble solid particles and liquid components of a mixture with the help of  a filter paper is known as filtration.

·        Magnetic Separation A magnet can be used to separate iron pieces which are attracted by a magnet from the other substance which is not attracted by the magnet like sand .The iron pieces sticks to the magnet but sand does not.

·        Solute: The substance which is dissolved is called solute. For example: when we dissolve salt in given quantity of water, the salt is known as solute.

·        Solvent: The substance in which the solute is dissolved is known as solvent.  For example: when you mix water and sugar. The water will be the solvent and the solute will be the sugar.

2.     Fill in Blanks:

·        The method of separating seeds of paddy from its stalk is called threshing .

·        When milk is cooled after boiling and poured on a piece of cloth , cream is left behind on it. This process of separating cream from milk is an example of___filtration_.

·        Impurities settle at the bottom when muddy water kept overnight in a bucket. Clear water was then poured from top. The process of separation used in this example is called _decantation.

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3.     what is handpicking ? When is this method used?

Answer:Handpicking is a method to remove slightly larger impurities like pieces of dirt,stones and husk from wheat,rice and pulses by hand. 

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4.    What is Winnowing? Where is it used?

Answer: Winnowing is a method to separate heavier and lighter components of a mixture by wind or by blowing air.

This method is commonly used by farmers to separate lighter husk particles from seeds of grains.

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5.    What is sieving? Where is it used?

Answer :Sieving is the method of separation of fine particles from bigger particles with the help of sieve.

It is used in homes to separate flour from impurities such as piece of stone, husk etc.

It is used in construction sites to separate sand from small stones.

6.   what is the difference between sedimentation and decantation?

Answer:Sedimentation is the process of settling down of heavy insoluble impurities.

Decantation is pouring out of clear water.

7.    How is salt obtained from sea water?

Answer:The sea water is first collected and it is kept for evaporation.When the water is fully evaporated the salt remains.By this way salt is obtained.

8.   How can we separate Oil and water?

Answer: Oil and water can be separated by decantation and sedimentation, Because water is heavier than oil and it settle at the bottom if we left it  undisturbed for some time.The oil can then simply be decanted or poured out.

9.   Why water is considered as universal solvent?

Answer: Water is called the "universal solvent" because it dissolves more substances than any other liquid. This is important to every living thing on earth. For example, the world is made up of 70% of water, and our bodies are also made up of 60% of water. Plants need water to survive and for preparing food.Most drinks or almost all drinks use water as solvent.