Solution of Chapter 5. Separation of Substances (NCERT - Science Exemplar Book)

Paheli bought some vegetables such as French beans, lady’s finger, green chilies, brinjal and potatoes all mixed in a bag. Which of the following methods of separation would be most appropriate for her to separate them?

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?

Which of the following mixtures would you be able to separate using the method of filtration?

Which amongst the following methods would be most appropriate to separate grains from bundles of stalks?

Four mixture 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?

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?

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?

(i) Evaporation

(ii) Decantation

(iii) Filtration

(iv) Churning

Which of the following combination is the correct answer?

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 back copper sulphate from the solution?

During summer, Boojho carries water in a transparent plastic bottle to his school. The bottle still had some water left in it. The following day, He observed some water droplets on the inner surface day, he observed some water droplets on the inner surface of the empty portion of the bottle. These droplets of water were formed due to

Paheli asked for a glass of water from Boojho. He gave her a glass of ice cold water. Paheli observed some water droplets on the outer surface of water were formed? Which of the following should be Boojho’s answer?

Sheela, Salma and Ravi have to dissolve maximum amount of sugar in the family 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 thick would win the game and why?

Fill in the blanks with appropriate words:

(i) Small pieces of stone can be removed from rice by ……………… .

(ii) …………….. are obtained from stalks by threshing.

(iii) Husk from wheat flour is generally removed by ………………. .

(iv) The process of settling of heavier particles is called ………………. .

(v) Filtration is helpful in separating an insoluble ………………. From a ………………….. .

State whether the following statement are True or false.

(a) A mixture of oil and water can be separated by filtration.

(b)Water can be separated from salt by evaporation.

(c) A mixture of wheat grains and wheat flour can be separated by sieving.

(d) A mixture of iron filing and rice can be separated by magnet.

(e) A mixture of wheat grains and rice flakes can be separated by winnowing.

(f) A mixture of tea leaves and milk can be separated by decantation.

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?

Match the mixture in Column I with their method of separation in Column II.

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 teaspoon full of salt and half a glass of water.

Paheli was feeling thirsty but there was only a pot of water at home which was muddy and unit 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.

Read the story titled ‘’ WISE FARMER’’ and tick the correct option to complete the story.

A farmer was sad/happy to see his healthy wheat crop ready for harvest. He harvested the crop and left it under the sun/rain to dry the stalks. To separate the seeds from the bundles of the stalk he handpicked/threshed them. After gathering the seed grains he wanted to separate the stones and husk from it. His wife winnowed / threshed them to separate the husk and later sieved/handpicked 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?

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.

A mixture of iron nails, salt, oil, and water is provided to you. Give stepwise methods to separate each component from this mixture?