Chapter 08 A Journey through States of Water Solutions
November 5, 2024Chapter 10 Living Creatures: Exploring their Characteristics Solutions
November 5, 2024Chapter 09 Methods of Separation in Everyday Life Solution
Text Book Solution
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Q1: What purpose does handpicking serve in the process of separation?
(i) Filtration
(ii) Sorting
(iii) Evaporation
(iv) Decantation
Ans: (ii) Sorting
Q2: Which of the following substances are commonly separated using the churning method?
(i) Oil from water
(ii) Sand from water
(iii) Cream from milk
(iv) Oxygen from air
Ans: (iii) Cream from milk
Q3: Which factor is usually essential for the filtration?
(i) Apparatus size
(ii) Presence of air
(iii) Pore size
(iv) Temperature of the mixture
Ans: (iii) Pore size
Q4: State with reason(s) whether the following statements are True [T] or False [F]. Also, correct the False statement(s).
(i) Salt can be separated from salt solution by keeping it under the Sun. [T]
Reason: The water will evaporate leaving the salt behind.
(ii) Handpicking should be used only when the quantity of one component is less. [T]
Reason: It is easier to handpick small quantities.
(iii) A mixture of puffed rice and rice grains can be separated by threshing. [F]
Correction: This mixture can be separated by handpicking or winnowing.
(iv) A mixture of mustard oil and lemon water can be separated by decantation. [T]
Reason: The oil and water will form separate layers which can be decanted.
(v) Sieving is used to separate a mixture of rice flour and water. [F]
Correction: Filtration is used to separate a mixture of rice flour and water.
Q5: Match the mixtures in Column I with their method of separation in Column II.
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Ans:
(a) → Handpicking
(e) → Filtration
(a) → Handpicking
(b) → Magnetic separation
(c) → Decantation
Q6: In what situations would you use decantation instead of filtration to separate solids from liquids?
Ans: Decantation is used when the solid particles are heavier and settle at the bottom of the liquid, such as in the case of sand and water. Filtration is used when the particles are small and suspended in the liquid.
Q7: Can you relate the presence of nasal hair to any separation process?
Ans: Nasal hair acts like a filter, trapping dust and other particles from the air we inhale, similar to how a filter paper traps solid particles from a liquid.
Q8: During the COVID-19 pandemic, all of us wore masks. Generally, what material are they made of? What is the role of these masks?
Ans: Masks are generally made of materials like cotton, synthetic fibers, or polypropylene. Their role is to filter out airborne particles, including viruses and bacteria, to prevent their inhalation and spread.
Q9: A mixture containing potatoes, salt, and sawdust has been given to you. Outline a stepwise procedure for separating each component from this mixture.
Ans:
Handpick the potatoes.
Add water to the remaining mixture to dissolve the salt.
Decant the water to separate the sawdust.
Evaporate the water to recover the salt.
Q10: Read the following story titled ‘Intelligent Leela’ and tick the most appropriate options. Provide a suitable title of your choice for the paragraph.
Leela was working in the farm with her father when she realised that they left their drinking water at home. Before her father felt thirsty/hungry, she went to the nearby pond to fetch some water/grains. After obtaining some water in the container, she noticed that the water was muddy and fit/unfit for drinking. To purify the water, she kept it for some time and then she filtered/churned the muddy water using a piece of paper/muslin cloth. Leela, then, cooled/boiled the water for about 10 minutes in a covered pan. After cooling/boiling, she filtered/churned it again and made it fit/unfit for drinking. She served this water to her father while having food, who blessed her and appreciated her efforts.
Ans:
Thirsty
Water
Unfit
Filtered
Muslin cloth
Boiled
Filtered
Fit
Suitable Title: “Leela’s Clever Solution for Clean Water”