Here in this post we provided NCERT Exemplar Problem Class 6 Science Separation of Substances Chapter 5 Full Explanation by group of Science Experts. We have provided here each questions answer with reason behind the answer.
Hope it help you!
Separation of Substances Class 6 Exemplar full Explanation:
Multiple Choice Questions
1) Paheli bought some vegetables such as french beans, lady’s finger, green chillies, brinjals, and potatoes all mixed in a bag. Which of the following methods of separation would be most appropriate for her to separate them?
a) Winnowing
b) Sieving
c) Threshing
d) Hand picking
Answer:- d) hand picking
Hand picking method will be applicable in For these situation. These vegetables will get easily hand picked and separated. Other methods are not applicable here.
2) Boojho’s grandmother is suffering from diabetes. Her doctor advised her to take ‘ Lassi’ with less fat content. Which of the following methods would be most appropriate for boojho to prepare it?
a) Filtration
b) Decantation
c) Churning
d) Winnowing
Answer:- c) churning
Churning is the appropriate method for making lassi. Other given methods are not applicable for making lassi.
3) Which of the following mixtures would you be able to separate using the method of filtration.
a) Oil in water
b) Cornflakes in milk
c) Salt in water
d) Sugar in milk
Answer:- b) cornflakes in milk
Cornflakes will be separated with filtration. It will remain on the filter paper and milk will be passed. Other mixtures will not be separated by filtration.
4) Which among the following methods would be most appropriate to separate grains from bundles of stalks?
a) Hand picked
b) Winnowing
c) Sieving
d) Threshing
Answer:- d) threshing
Threshing is the method which is used to separate the grains from bundles of stalks. Threshing will remove grains. Other methods are not appropriate here.
5) Four mixtures are given below
i) Kidney beans and chick peas
ii) pulses and rice
iii) rice flakes and corn
iv) potato wafers and biscuits
Which of these can be separated by the method of winnowing?
a) I) and ii)
b) Ii) and iii)
c) I) and iii)
d) iii) and iv)
Answer:- d) iii) and iv)
Winnowing method will be used for the separation of rice flakes and corn . Rice flakes will be fall down and corn flakes will blown away with air. And potato wafers and biscuits will be also separate by Winnowing.
6) While preparing chapatis, paheli found that the flour to be used was mixed with wheat grains. Which out of the following is the most suitable method to separate the grains from the flour?
a) Threshing
b) Sieving
c) Winnowing
d) Filtration
Answer:- b) sieving
Sieving will be separate the grains from flour by strainer. Flour will be fall down and grain will remained up.
7) You might have observed the preparation of ghee from butter and cream at home. Which method(s) can be used to separate ghee from the residue?
a) Evaporation
b) Decantation
c) Filtration
d) Churning
Which of the following combination is the correct answer?
a) I) and ii)
b) ii) and iii)
c) ii) and iv)
d) iv) only
Answer:- b) ii)and iii)
Decantation and filtration will be used to separate the ghee from residues.
8) In an activity, a teacher dissolved a small amount of solid copper sulphate in a tumbler half filled with water. Which method would you use to get back solid copper sulphate from the solution?
a) Decantation
b) Evaporation
c) Sedimentation
d) Condensation
Answer:- b) Evaporation.
Evaporation will be used here. Water will get evaporated and solid copper sulphate will be get back from the solution.
9) During summer, boojho carries water in a transparent plastic bottle to his school. One day he left his bottle in the school. The bottle a had some water droplets on the inner surface of the empty portion of the bottle. These droplets of water were formed due to
a) Boiling and condensation.
b) Evaporation and saturation.
c) Evaporation and condensation.
d) Condensation and saturation.
Answer:- c) Evaporation and condensation.
Water is get evaporated and turns into vapours. It when cools down then by condensation it forms the Again liquid water from the vapour.
10) Paheli asked for a glass of water form boojho . He gave her a glass of ice cold water. Paheli observed some water droplets on the outer surface of the glass and asked boojho how these droplets of water were formed? Which of the following should be boojho’s answer?
a) Evaporation of water from the glass.
b) Water that seeped out from the glass.
c) Evaporation of atmospheric water vapour.
d) Condensation of atmospheric water vapour.
Answer:- d) condensation atmospheric water vapour.
The vapours are condensed and form liquid water again.
-
Very Short Answer Questions
11) Sheela, Saima and Ravi have to dissolve maximum amount sugar in the same amount of milk so as to win in a game. Ravi took hot boiling milk while Saima took ice cold milk. Sheela managed to get milk at room temperature. Whom do you think would win the game and why?
Answer:- Ravi which have taken the hot boiling milk will win the game. Because the maximum amount of sugar will get dissolve faster in the boiling milk. As the temperature is highest of the that milk. Other don’t have that much of temperature thus the sugar will not dissolve fast in others milk. Therefore Ravi will win the game.
12) Fill in the blanks with appropriate words:-
i) Small pieces of stone can be removed from rice by ________.
Answer:- small pieces of stone can be removed from rice by hand picking.
ii) ____________ are obtained from stalks by threshing.
Answer:- grains are obtained from stalks by threshing.
iii) Husk from wheat flour is generally removed by __________.
Answer:- Husk from wheat flour is generally removed by sieving.
iv) The process of setting of heavier particles is called ____________.
Answer:- The process of setting of heavier particles sedimentation .
v) Filtration is helpful in separating an insoluble ___________ from a ___________.
Answer:- Filtration is helpful in separating an insoluble solid from a liquid.
13) statewhether the following statements are true or false .
1) A mixture of oil and water can be separated by filtration.
Answer:- False
A mixture of oil and water can be separated by Decantation.
2) Water can be separated from salt by evaporation.
Answer:- True
3) A mixture of wheat grains and wheat flour can be separated by sieving.
Answer:- True
4) A mixture of iron filings and rice flour can be separated by magnet.
Answer:- True
5) A mixture of wheat grains and rice flakes can be separated by winnowing .
Answer:- True
6) A mixture of tea leaves and milk can be separated by decantation.
Answer:- True
-
Short Answer Questions
14) Name and describe briefly a method which can be helpful in separating a mixture of husk from grains. What is the principle of this method?
Answer:-
The method which can be used for separating husk from the grains is Winnowing.
Winnowing is carried out to separate the Heavier or lighter components in the mixture by blowing wind or air. Husk are lighter in weight. It easily blown away with the air. In these process grains are taken in soop or any flattened substance. And when the wind is blowing soop is taken to the height. Grains are left from the height and lighter particles like husk and dust are carried out with blowing air which is falls on some distance from the grains. Thus the grains and husk are separated.
15) Match the mixtures in column I with their method of separation in column II.
Column I | Column II |
a) Oil mixed in water | i) Sieving |
b) Iron powder mixed with flour | ii) Hand picking |
c) Salt mixed with water | iii) Decantation |
d) Lady’s finger mixed with French beans | iv) Magnet |
e) Rice flour mixed with kidney beans | v) Evaporation |
A) Oil mixed in water – iii) Decantation.
B) Iron powder mixed With flour – iv) Magnet.
C) Salt mixed with Water – v) Evaporation.
D) Lady’s finger Mixed with French beans – ii) Hand picked.
E) Rice flour mixed With kidney Beans – i) Sieving.
-
Long Answer Questions
16) Both sarika and mohan were asked to make salt solution. Sarika was given a teaspoonful of salt and half a glass of water, whereas mohan was given twenty teaspoons full of salt and half a glass of water.
a) How would they make salt solutions?
Answer:-.
They will make salt solution by mixing salt into the water.
b) Who would be able to prepare saturated solution?
Answer:- In Mohan’s solution some amount of salt is remained undissolved and that salt is settled down at the bottom. This means that the solution cannot dissolve more amount of salt in given amount of water. Thus the solution becomes saturated. Therefore Mohan’s solution is saturated solution.
17) Paheli was feeling thirsty but there was only a pot of water at home which was muddy and unfit for drinking. How do you think paheli would have made this water fit for drinking if the following materials were available to her.
Alum, tub, muslin cloth , gas stove , thread, pan and lid.
Answer:-
i) Filtration of muddy water using muslin cloth.
ii) It could be swirl with alum and leave it untouched for sometime, so that the mud or minute soil particles will settle down to the pot and clean, clear water will be on top.
iii) After that the process of decantation can be carried out.
iv) Further it may be boil for 10 – 15 minutes with covered pan.
v) Filter the boiled water and let it cool. Now the water is fit for drinking.
18) Read the story sad/ happy to see his healthy wheat crop ready for harvest. He harvested the crops and left it under the sun/ rain to dry the stalks. To separate the seeds from the bundles of the stalk he handpicked / threshed After gathering the seed grains he wanted to separate the stones and huskfrom it. His wife winnowed/ threshed them to separate the husk and later sieved/ hand picked to remove stones from it. She ground the wheat grains and sieved/ filtered the flour. The wise farmer and his wife got a good price for the flour. Can you tell why?
Answer:-
Happy to see his healthy wheat crop ready for harvest. He harvested the crops and left it under the sun to dry the stalks. To separate the seeds from the bundles of the stalk he threshed them. After gathering the seed grains he wanted to separate the stones and husk from it. His wife winnowed them to separate the husk and later handpicked to remove stones from it. She ground the wheat grains and sieved the flour.
The wise farmer and his wife got a good price for the flour because the farmer and his wife used the proper methods of separation of the grains for the good quality of floor and thus got good price.
19) You are provided with a mixture of salt, sand, oil and water. Write the steps involved for the separation of salt, sand and oil from the mixture by giving an activity along with the diagram.
Answer:-
The given mixture contains salt, sand , oil and water. These components will be separate from each other as follows-
Decantation
Decantation will be used for the separation of oil from the mixture. The oil floats over the water surface. Thus the water along with the oil is removed which is known as decantation. The remaining part of the mixture which is settled down is known as sedimentation. Which is further removed.
Filtration
Filtration process will be carried out to separate sand from the mixture. Muddy water and slightly smaller particles like dust and sand are removed by filtration. In filtration process a filter paper is used as strainer. Filter paper is fixed in the funnel by making it come shaped. Then the mixture will be poured on the paper. Solid particles does not pass through the filter paper and thus remains on it and the water along with salt will be strained through the paper.
Evaporation
Salt and water can be separated by the process known as evaporation.
Salt water is taken in the beaker and then heated it with a slow flame. Water will be vaporized and the salt will remained in the beaker.
Thus all the components of the mixture will be separated by using these steps.
20) A mixture of iron nails, salt, oil and water is provided to you. Give stepwise methods each component from this mixture?
Answer:-
The given mixture contains iron nails, salt , oil and water , these are separated as follows-
Firstly iron nails are larger in size thus, these Iron nails are separated by the handpicking method or it can also be separated by using a magnet. Iron nails will easily attached to the magnet and taken out with it. Thus the nails will be separated from the mixture.
Later, oil will be separated from the mixture by using the method of Decantation. Oil will float on the water and the remaining component salt will be settled down the water. The water along with the oil is removed then the process is called as decantation.
Next is only water and salt solution is remaining. These mixture will be separated by using the method of evaporation. When the water is evaporated it turns into vapours. Vapours will be pass in the air and only salt will be remained. Also water can be retained from the vapours by the process of condensation. Vapours are condensedand forms liquid water again. Thus the total components of the mixture will be separated.