NCERT Solutions for Class 6 Science Chapter 9 Methods of Separation in Everyday Life

NCERT Solutions for Class 6 Science Chapter 9 Methods of Separation in Everyday Life  दैनिक जीवन में पृथक्करण की विधियाँ

Question 1.
A small amount of puffed rice is mixed with chana dal. Can you think of separating the mixture by any method other than handpicking?
चने की दाल में मुरमुरों की थोड़ी मात्रा मिल गई है। क्या आप हस्त चयन के अलावा किसी अन्य विधि से इस मिश्रण को पृथक करने के विषय में सोच सकते हैं?
Answer:
Yes, the other method is winnowing.
हाँ, दूसरी विधि ओसाई (विनोइंग) है।

Question 2.
Valli is unable to separate husk from rice in a closed room. How can you help her? 
वल्ली बंद कमरे में चावल से भूसी अलग नहीं कर पा रही है। आप उसकी मदद कैसे कर सकते हैं?
Answer:
We can help her by placing a fan for air blowing the light husk.
हम हल्की भूसी को हवा देने के लिए पंखा लगाकर उसकी मदद कर सकते हैं।

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(Page No. 178-179-180)

Question 1.
What purpose does handpicking serve in the process of separation?
(i) Filtration
(ii) Sorting
(iii) Evaporation
(iv) Decantation
Answer:
(ii) Sorting

Question 2.
Which of the following substances are commonly separated using the churning method?
(i) Oil from water
(iii) Cream from milk
(ii) Sand from water
(iv) Oxygen from air
Answer:
(iii) Cream from milk

Question 3.
Which factor is usually essential for the filtration?
(i) Apparatus size
(ii) Presence of air
(iii) Pore size
(iv) Temperature of the mixture
Answer:
(iii) Pore size

Question 4.
State with reason(s) whether the following statements are True [T] or False [F]. Also, correct the False statements).
(i) Salt can be separated from ‘ salt solution by keeping it under the Sun.
(ii) Handpicking should be used only when the quantity of one component is less.
(iii) A mixture of puffed rice and rice grains can be separated by threshing.
(iv) A mixture of mustard oil and lemon water can be separated by decantation.
(v) Sieving is used to separate a mixture of rice flour and water.
Answer:
(i) True
Reason : The water will evaporate leaving the salt behind.

(ii) True
Reason: It is easier to handpick small quantities.

(iii) False
Reason: Process of threshing is used to separate the grains from the stalks.
Correct statement: This mixture can be separated by handpicking or winnowing.

(iv) True
Reason: The oil and water will form separate layers which can be decanted.

(v) False
Reason: Sieving is done to separate solid-solid mixture of different particles size.
Correct Statement: Filtration is used to separate a mixture of rice flour and water.

Question 5.
Match the mixtures in Column I with their method of separation in Column II.
Answer
(i)-(d); (ii)-(e); (iii)-(a); (iv)-(b); (v)-(c)

Question 6.
In what situations would you use decantation instead of filtration to separate solids from liquids?
Answer:
Decantation method is used when the insoluble solid particles are heavier and settle down at the bottom of the vessel. The liquid is separated from insoluble solids by pouring off the liquid while leaving the solid particles behind as a residue.
While filtration method is used when insoluble particles do not settle down and spreads throughout the solution.

Question 7.
Can you relate the presence of nasal hair to any separation process?
Answer:
Nasal hair acts like a natural filter, trapping dust, pollen, and other particles from the air we breathe, similar to how a filtration process works to remove solid impurities from a liquid.

Question 8.
During the COVID-19 pandemic, all of us wore masks. Generally, what materials are they made of? What is the role of these masks?
Answer:
Masks are generally made of multiple layers of fabric or materials such as cotton, polypropylene, or polyester. Their role is to filter out harmful particles, including viruses, from the air we breathe, similar to how filtration processes work to remove impurities from liquids.

Question 9.
A mixture containing potatoes, sctlt and sawdust has been given to you. Outline a stepwise procedure for separating each component from this mixture.
Answer:
Step-1 : Handpick the potatoes
Step-2 : Add water to the remaining mixture to dissolve the salt
Step-3 : Filter the mixture to separate the sawdust from the salt solution.
Step-4 : Evaporate the water from the salt solution to obtain the salt.

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