NCERT Class 6 Science – Separation of Substances Chapter 5 Question Answer for Preparation of Exams. Here we Provide Class 6 Vigyan Question Answer, Important Questions, for Various State Boards Students like CBSE, Haryana, uttar pradesh, mp and other state students.
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NCERT Class 6 Science Chapter 5 Separation of Substances Question Answer ( अभ्यास के प्रश्न उत्तर ) Solution.
Separation of Substances Class 6 Science Chapter 5 Question Answer
Textual Questions and Answer for Easy to Understand the Chapter of Science.
Q. 1. Why do we need to separate different components of a mixture ? Give two examples.
Ans. The unwanted substances are needed to be removed from the mixture because of the following purposes.
(i) To remove the non-useful or harmful components. 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 particles of wheat on the basis of their density. This method is used by farmers in fields as well as at a flour mill (atta chakki). In this method, the wheat grains containing husk are allowed to fall down from some height while the wind is blowing. Lighter husk is carried away by wind and we get heavier grains making a separate heap.
Q.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, if any is removed by decantation .
Q. 4. What is sieving ? Where is it used ?
Ans. Sieving. It is a method used to separate various substances of different sizes with the help of a sieve (coarse cloth, filter paper or mesk). Sieving the wheat flour (atta) is a common method.
Sieving the wheat flour allows the 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. Separating sand and water from their mixture. A mixture of sand and water is separated by decantation. Take a beaker with given sample of water. Stir it and keep it aside undisturbed for some time. Being heavier, sand settles down as the bottom of the 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 the process of sieving
Take the mixture in the sieve. Rotate it gently. Fine flour particles pass through the holes of the sieve while the bigger particles of sugar remain on the sieve
Q. 7. How would you obtain clear water from a sample of muddy water ?
Ans. Cleansing of muddy water:- In muddy water, the alum is used to load the fine clay particles which become heavier and settle down. Then the clear water is decanted off.
Method:- Take glass beaker of capacity 100 ml. Fill it half with the given sample of muddy water. Tie a piece of Alum (phitkari) to one end of thread piece. Hold it firmly from the free end of the thread and dip alum piece in muddy water. Move it slowly in water for about 2-3 minutes. Remove the alum piece and let it be undisturbed for some time. After some time you would notice that dust particles have settled down after getting heavier and water has become clear. The clear water is now decanted off into another beaker.
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) threshing
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 by the process of decantation.
Ans. (a) False (b) False (c) False (d) 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 will be easily dissolved in lemonade before adding ice because solubility increases with the increase in temperature.