NCERT Class 6 Science Chapter 5 Question Answers cover the book exercise in a simplified and precise way. NCERT Class 6 Science Chapter 5 Question Answers are easy to understand and learn for exams.
#Separation of Substances
NCERT Class 6 Science Chapter 5 Question Answers
1. Why do we need to separate different components of a mixture? Give two examples.
Answer: Some components of a mixture are harmful or unuseful to us. So, we need to separate these components from the mixture.
Examples:
(1) Separation of small stones from grains.
(2) Separation of dirty from water.
2. What is winnowing? Where is it used?
Answer: Winnowing is the process of removing lighter particles from heavier particles of a mixture by wind or blowing air.
3. How will you separate husk or dirt particles from a given sample of pulses before cooking.
Answer: By the process of winnowing, lighter husk or dirt particles are separated from heavier pulses.
4. What is sieving? Where is it used?
Answer: Sieving is a process of separating small fine particles from bigger particles with the help of a sieve.
> Sieving is used in flour mil to separate husks and stones from wheat grains.
> Sieving is also used at construction sites to separate stones from sand.
5. How will you separate sand and water from their mixture?
Answer: Sand and water can be separated by sedimentation and decantation method. The mixture is kept for some time so that the heavier sand settle at the bottom. Then Water can be poured into another container by decantation.
6. Is it possible to separate sugar mixed with wheat flour? If yes, how will you do it?
Answer: Sugar and wheat flour particles have different sizes. These particles can be separated by sieving.
Sugar will stay on the sieve and flour will pass through it.
7. How would you obtain clear water from a sample of muddy water?
Answer: Clear water can be obtained from muddy water by the process of filtration.
> A filter paper is one such filter that has very fine pores in it.
> The filter paper is folded into a cone. This cone is place on a funnel.
> The mixture is then poured on the filter paper.
> Solid particles in the mixture do not pass through it and remain on the filter.
> Water passes through the filter paper and we get clear water.
8. Fill up the blanks
(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 filteration.
(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 Sedimentation and Decantation.
9. True or false?
(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
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: More sugar can be added to water at higher temperature. After adding ice, the mixture gets cool and less sugar will be dissolved in it. Hence, ice should be added after mixing sugar.