NCERT Solutions for Class 6 Science Chapter 09 Methods of Separation in Everyday Life

Question 1. What purpose does handpicking serve in the process of separation?
(i) Filtration
(ii) Sorting
(iii) Evaporation
(iv) Decantation
Answer: (ii) Sorting
In simple words: Handpicking means using your hands to pick out unwanted items from a mixture. This is a type of sorting - separating things by choosing what you want and what you don't want.

Exam Tip: Remember that handpicking is a manual separation method best suited for mixtures with large solid particles that are easy to see and grab.

Question 2. 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
Answer: (iii) Cream from milk
In simple words: Churning means stirring or shaking a mixture in a circular motion. This separates cream from milk because the vigorous motion causes the cream particles to clump together and float to the top.

Exam Tip: Churning is used specifically for separating cream from milk - it's a traditional and important method in dairy processing.

Question 3. Which factor is usually essential for the filtration?
(i) Apparatus size
(ii) Pore size
(iii) Presence of air
(iv) Temperature of the mixture
Answer: (ii) Pore size
In simple words: The size of the holes (or pores) in the filter is what matters most. The pores must be small enough to catch the unwanted particles but large enough to let the liquid pass through.

Exam Tip: For filtration to work well, choose the right filter material - one with pores the right size for what you're trying to separate.

Question 4. 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.
(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) Salt can be separated from salt solution by keeping it under the Sun. - True (T)
(ii) Handpicking should be used only when the quantity of one component is less. - True (T)
(iii) A mixture of puffed rice and rice grains can be separated by threshing. - False (F)
Corrected Statement: A mixture of puffed rice and rice grains can be separated by winnowing.
(iv) A mixture of mustard oil and lemon water can be separated by decantation. - True (T)
(v) Sieving is used to separate a mixture of rice flour and water. - False (F)
Corrected Statement: Sieving is used to separate a mixture of different sized solid particles, not for separating solid from liquid.
In simple words: True/False questions test whether you know which separation method works for which mixture. Remember - threshing removes grains from stalks, winnowing blows away lighter bits, and sieving sorts solids by size.

Exam Tip: When correcting false statements, state the right method clearly and briefly explain why it's the correct one for that mixture.

Question 5. Match the mixtures in Column I with their method of separation in Column II.

Answer:

In simple words: Different mixtures need different methods. Pick the method that matches what the mixture contains - solids of different sizes need sieving, liquids and solids need filtration, and things attracted to magnets need magnetic separation.

Exam Tip: Learn which separation method works for each type of mixture by thinking about the size and properties of what you're trying to separate.

Question 6. In what situations would you use decantation instead of filtration to separate solids from liquids?
Answer: Decantation works best when the solid particles are large and heavy enough to sink quickly to the bottom of the container. The liquid on top can then be poured off carefully without the solid settling mixed back in. This method is ideal for separating sand from water, for instance, where the sand particles settle out completely and the water stays clear above them. The advantage is that decantation doesn't require any special equipment like filter paper - just a careful hand to pour the liquid away.
In simple words: Use decantation when the solid particles are heavy and sink fast to the bottom. Filtration is better when particles are very small or the solid is spread throughout the liquid.

Exam Tip: Decantation saves time and materials compared to filtration, but only works when solids settle clearly - examiners want to see you understand when to pick which method.

Question 7. Can you relate the presence of nasal hair to any separation process?
Answer: Nasal hair functions as a natural filter inside the nose. It traps dust, pollen, and other tiny particles from the air we breathe, much like how filtration removes solid impurities from liquids. The nasal hairs prevent these unwanted particles from entering our lungs and keep our airways clean. Just as a filter lets clean fluid pass while catching unwanted solids, nasal hair lets clean air reach our lungs while blocking harmful dust and particles.
In simple words: Nasal hair is like a filter in your nose. It catches dust and pollen from the air so they don't go into your lungs.

Exam Tip: This question tests whether you can connect filtration to real-life examples - showing you understand the concept beyond just textbook definitions.

Question 8. During the COVID-19 pandemic, all of us wore masks. Generally, what material are they made of? What is the role of these masks?
Answer: Masks are typically made from multiple layers of fabric or synthetic materials such as cotton, polypropylene, or polyester. These layers work together to filter out harmful particles, including viruses, from the air we breathe. The role of the mask is similar to how filtration works in separating unwanted particles from liquids - it acts as a barrier that traps tiny droplets and particles containing germs while still allowing us to breathe clean, safer air. The layered structure ensures that particles of different sizes are caught, providing protection for both the wearer and those around them.
In simple words: Masks have several layers of fabric that catch germs and particles in the air, like a filter. They work the same way filtration keeps bad stuff out of water.

Exam Tip: Connect mask function directly to filtration - explain how layers trap particles, and mention that this principle is the same as lab filtration methods.

Question 9. A mixture containing potatoes, salt and sawdust has been given to you. Outline a stepwise procedure for separating each component from this mixture.
Answer:
Step 1: Handpick the potatoes out of the mixture.
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.
In simple words: Pick out the big potatoes by hand first. Then add water to dissolve the salt. Filter out the sawdust. Finally, heat the salty water to evaporate the water and get the salt back.

Exam Tip: Always arrange steps in logical order - remove large items first, then work with solutions. Examiners look for correct sequencing of methods.

Question 10. 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 and appreciated her efforts.

Answer: Suitable title: Leela's Clever Water Purification
In simple words: Leela used two separation methods to clean the water - first filtration to remove mud, then boiling to kill germs. Her title shows she was smart about making water safe to drink.

Exam Tip: For comprehension questions, choose a title that captures the main action and shows understanding of the concept - here, water purification is the key idea.