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NCERT Solutions for Class 6 Science Chapter 5 Separation of Substances

NCERT solutions of class 6 science Chapter 5 Separation of materials is provided here with a set of some additional important question like Multiple choice questions and very short answer type questions. In this solutions all the questions are explained in simple words so that the students can understand it better without any difficulty.

Note: If you have any doubt related to any questions of this chapter you can comment your doubt without any hesitate and I will answer it in less than 24hours of time.

Q. 1. Why do we need to separate different components of a mixture ? Give two examples.

Ans. The unwanted substances are needed to remove from the mixture because of the

following purposes:

(i) To remove the un-useful or harmful compoments. For example, removing tea leaves after making tea.

(ii) To obtain the useful component. For getting wheat/rice grain after separating husk, dirt etc.

(iii) To remove impurities for getting a pure sample. For example obtaining sugar crystals from jaggery (gur) or salt from sea water.

Q.2. What is Winnowing ? Where is it used ? 

Ans. Winnowing. It is a method used to separate lighter husk particles from heavier grains of wheat on the basis of their density. In this method, the wheat grains containis husk are allowed to fall down from some helg  while the wind is blowing. Lighter husk carried away by wind and make a separate heap and we get heavier grains. The husk is used as fodder of animals.

3. How will you separate husk or dirt particles from a given sample of pulses before cooking?

Ans. Separating husk or dirt from pulses. To separate husk or dirt particles, method of hand picking is used. Then pulses or rice are washed with water. Dust or dirt dissolves in water. Since the pulses or rice grains are heavy, they settle down at the bottom of the container and dissolved dust is removed by decantation.

Q.4. What is Sieving? Where is it used ?

Ans. Sieving :- It is method used to separate various substances of different sizes with the

help of a sieve (coarse cloth, filter paper or mesh). Sieving the wheat (atta) is a common method. 

Sieving the wheat flour through a sieve allows fine particles of the flour to pass through

the holes of the sieve while bigger husk particles remain on the sieve.

Q.5. How will you separate sand and water from their mixture ?

Ans. Filter the mixture of sand and water with the help of filter paper. Sand will be left behind on paper while water will filter down A mixture of sand and water can be separated by decantation. Take a beaker with given sample of water. Stir it and keep aside

undisturbed for some time. Being heavier sand is settled down in beaker. Now pour the clean water in another beaker. In this way, sand and water are separated.

Q. 6. Is it possible to separate sugar mixed with wheat flour ? If yes, how will you do it ?

Ans. Yes, the sugar can be separated from wheat flour by process of sieving.

Take the mixture in the sieve. Fine flour particles pass through the holes of the sieve

while sugar remains on the sieve.

Q. 7. How would you obtain clear water from a sample of muddy water ?

Ans. Take some muddy water in a container and keep it aside for half an hour. Particles will settle down at the bottom as they are heavier. Now pour the water in other glass.

This method is known as decantation.

lf water is still muddy or brownish in colour, then filter it, For filtration use filter

paper to clear the muddy water, Impurities will be left behind on the filter paper. In this

way muddy water will get clear.

Q.8. Fill up the blanks :

(a) The method of separating seeds of paddy from its stalks is called ………….. .

(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai)

is left behind on it. This process of separating cream from milk is an example of ………. .

(c) Salt is obtained from sea water by the process of ………... .

(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called ……..... .

Ans.

(a) The method of separating seeds of paddy from its stalks is called Threshing .

(b) When milk, cooled after boiling, is poured onto a piece of cloth the cream (malai)

is left behind on it. This process of separating cream from milk is an example of Filtration. .

(c) Salt is obtained from sea water by then process of Evaporation .

(d) Impurities settled at the bottom when muddy water was kept overnight in a bucket. The clear water was then poured off from the top. The process of separation used in this example is called Decantation .

Q.9. True or false:

(a) A mixture of milk and water can be separated by filtration.

(b) A mixture of powdered salt and sugar can be separated by the process of winnowing.

(c)Separation of sugar from tea can be done with filtration.

(d) Grain and husk can be separated with the process of decantation.

Ans. (a) A mixture of milk and water can be separated by filtration. (False)

(b) A mixture of powdered salt and sugar can be separated by the process of winnowing. (False)

(c)Separation of sugar from tea can be done with filtration. (False)

(d) Grain and husk can be separated with the process of decantation. (False)

Q.10. Lemonade is prepared by mixing lemon juice and sugar in water. You wish to add ice to cool it. Should you add ice to the lemonade before or after dissolving Sugar ? In which case would it be possible to dissolve more sugar ?

Ans. Sugar is dissolved first while preparing lemonade because if we add sugar after adding ice then lemonade will be cooled Then due to low temperature sugar will not

dissolve. So, sugar must be dissolved before adding ice to lemonade.

Additional Important Questions

 Multiple Choice Questions(MCQ)

1. Separation of stone from pulses can be done by -

a) Sieving

b) Winnowing

c) Handpicking

d) None

Ans. c) Handpicking 

2. Winnowing method is used to separate light particles from .......... particles.

a) Heavy

b) Hard

c) Big and Light 

d) All of these

Ans. a) Heavy

3. Used to separate husk and dust particles from wheat flour is -

a) Air

b) Hand

c) Sieve

d) Water

Ans. b) Sieve.

4. The process of separating husk from grains is -

a) Threshing

b) Hand Picking

c) Winnowing

d) Sieving

Ans. a) Threshing

Very Short Answer Type Questions

Q. 1. Why do we separate substances ?

Ans. To get useful substances after separating it from harmful substances.

Q.2. What are different methods of separation?

Ans. Methods of separation :-

Handpicking, Threshing, Winnowing, Decantation, Sedimentation and Filtration.

Q.3. What is Hand Picking?

Ans. Hand Picking :- The method of hand picking is used to separate large soil particles,

stones and husk from wheat, rice and pulses.

Q.4. What is Threshing ?

Ans. Threshing :- The process of separating grains from the stalks is called threshing.

Q. 5. When the method Winnowing is used for separations?

Ans. Winnowing :- When the particles of impurities are light then winnowing method

is used to separate them. Farmers use this method to separate husk from wheat grains.

NCERT Solutions for Class 6 Science – All Chapters

Chapter 1 Food Where Does It Come From

Chapter 2 Components of Food

Chapter 3 Fibre to Fabric

Chapter 4 Sorting Materials Into Groups

Chapter 5 Separation of Substances

Chapter 6 Changes Around Us

Chapter 7 Getting to Know Plants

Chapter 8 Body Movements

Chapter 9 The Living Organisms and Their Surroundings

Chapter 10 Motion and Measurement of Distances

Chapter 11 Light Shadows and Reflection

Chapter 12 Electricity and Circuits

Chapter 13 Fun with Magnets

Chapter 14 Water

Chapter 15 Air Around Us

Chapter 16 Garbage In Garbage Out.