Question answers and excersie
1. Why Do We Need to Separate Different Components of the Mixture? Give Two Examples.
Ans: We need to separate harmful or non-useful components of a mixture that may be mixed with it to obtain a better mixture. Sometimes, even useful components are often separated if we’d like to use them separately.
2. What is Winnowing? Where is it Used?Ans: The process of separation of heavier and lighter components of a mix by wind or blowing air is known as winnowing. Farmers use the method of winnowing to separate husk particles from seeds of grains.
3. How Will You Separate Husk or Dirt Particles from a Given Sample of Pulses Before Cooking?Ans: The method of handpicking is used for separating Husk or dirt particles from a sample of pulses. Handpicking is a process by which slightly large-sized particles can be separated. We chose to handpick when the impurities are less.
4. What Is Sieving? Where Is it Used?
Ans: sieving allows the particles to pass through the holes of the sieve while bigger impurities remain on the sieve thus this process allows to separate particles which differ in their size. It is mainly used in flour mills to remove impurities like stones and husk.
5. How Will You Separate Sand and Water from Their Mixture?
Ans: The process of sedimentation and decantation can be used for the separation of sand and water from their mixture. Allow the mixture of sand and water to stand still in the container until the sand settles at the bottom. Now a layer of sand and a layer of water is formed in the container. Now gently, pour the water into another container. Thus, we can separate them.
6. Is it Possible to Separate Sugar Mixed With Wheat Flour? If Yes, How Will You Do It?
Ans: Sugar mixed with wheat flour can be separated. So, it is possible. This can be done by the process of sieving as the particles of wheat flour differ in size from sugar.
7. How Would You Obtain Clear Water from a Sample of Muddy Water?
Ans: The process of filtration can be used in order to obtain clear water from the sample of muddy water. For this process, muddy water is allowed to pass through a filter paper. Where the mud is collected on the filter paper and water passes through it.
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 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.
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.
Solution:
a) False
b) False
c) False
d) 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?
ANs.Ice should be added to lemonade after dissolving sugar. It is possible to add more sugar before adding ice.
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