# NCERT Solutions for Class 6 Science Chapter 5 Separation of Substances

Class 6 Science Chapter 5 Textbook Questions Answer Solved

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

Answer:- Sometimes we need to separate different components of a mixture because here are many substances which are harmful or not useful for us in it. Two examples are:-

(a) Tea leaves are to be separated from the tea before serving.

(b) Stone pieces from rice and pulses are picked out by hand before cooking.

Question 2. What is winnowing? Where is it used?

Answer:- The method of separating heavier and lighter components of a mixture by wind or by blowing air is called winnowing. This method is commonly used by farmers to separate lighter husk particles from heavier seeds of grain.

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

Answer:- We can separate husk or dirt particles from a given sample of pulses before cooking by the process called winnowing.

Question 4. What is sieving? Where is it used?

Answer:- The process by which fine particles are separated from bigger particles by using a sieve is called Sieving. It is used in construction sites Pebbles and stones are removed from sand.

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

Answer:- We will separate sand and water by sedimentation and decantation method by following given steps:-

1. We will left the mixture undisturb for few minutes until sand settles down.
2. Then we will Slowly pour the water into another container to obtain sand in the bottom.

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

Answer:- Yes, it possible to separate sugar mixed with wheat flour by sieving method.

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

Answer:- We will obtain clear water from a sample of muddy water by the process of filtration by following given steps:-

1. We will left the muddy water undisturb for few minutes until mud settles down.
2. Then we will Slowly pour the water into another container to obtain mud in the bottom.

Question 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 seawater 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 ___________.

(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 seawater by the 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

Question 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.

(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 )

Question 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?

Answer:-  We should add ice after dissolving sugar because then It would possible to add more sugar in it. The higher the temperature the more sugar can be dissolved. After mixing ice in lemonade it gets cool and less sugar will dissolve in it.

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