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Methods of Separation — Homi Bhabha Class 6 Chemistry MCQs with Solutions
Free Homi Bhabha Class 6 Chemistry Methods of Separation MCQs with step-by-step solutions covering Filtration & Evaporation, Winnowing & Sieving, Sedimentation & Decantation, Magnetic Separation & Distillation. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — Filtration & Evaporation · easy · theory
Filtration is used to separate …
A. Salt that is dissolved in water
B. Sugar dissolved in milk
C. Two gases from each other
D. An insoluble solid from a liquid ✓ Correct
Solution: Filtration separates an insoluble solid, such as sand, from a liquid because the solid cannot pass through the filter paper.
Q2 — Filtration & Evaporation · easy · theory
Which method is used to separate tea leaves from tea?
A. Filtration (using a strainer) ✓ Correct
B. Using a magnet
C. Evaporation
D. Winnowing
Solution: A strainer is a kind of filter; the tea leaves stay back while the liquid tea passes through, so it is filtration.
Q3 — Filtration & Evaporation · easy · theory
In filtration, the solid left behind on the filter paper is called the …
A. Solution
B. Vapour
C. Filtrate
D. Residue ✓ Correct
Solution: The solid that stays on the filter paper is called the residue.
Q4 — Filtration & Evaporation · easy · theory
The clear liquid that passes through the filter paper is called the …
A. Residue
B. Filtrate ✓ Correct
C. Sediment
D. Husk
Solution: The liquid that passes through the filter paper is called the filtrate.
Q5 — Winnowing & Sieving · easy · theory
Winnowing is mainly used to separate …
A. Two liquids
B. Salt from water
C. Iron from sand
D. Heavier grain from lighter husk ✓ Correct
Solution: Winnowing separates the heavier grain from the lighter husk (chaff).
Q6 — Winnowing & Sieving · easy · theory
Winnowing uses moving …
A. A magnet
B. Air (wind) ✓ Correct
C. Water
D. A filter
Solution: Winnowing uses wind (moving air) to blow away the light husk while the heavier grain falls straight down.
Q7 — Winnowing & Sieving · easy · theory
A sieve is used to separate things that are of different …
A. Tastes
B. Colours
C. Sizes ✓ Correct
D. Smells
Solution: A sieve has small holes, so it separates a mixture into parts of different sizes.
Q8 — Winnowing & Sieving · easy · theory
When flour is sieved, the fine flour passes through the holes and what stays back on the sieve?
A. Air
B. The larger bits of bran or husk ✓ Correct
C. Sugar
D. Water
Solution: The fine flour falls through the tiny holes, while the bigger pieces of bran or husk are too large and stay on the sieve.
Q9 — Sedimentation & Decantation · easy · theory
When a glass of muddy water is left still for some time, the mud slowly …
A. Rises to the top
B. Settles at the bottom ✓ Correct
C. Turns into salt
D. Disappears completely
Solution: The heavier mud particles are insoluble and slowly settle down at the bottom. This settling is called sedimentation.
Q10 — Sedimentation & Decantation · easy · theory
The heavier solid that settles down at the bottom is called the …
A. Filtrate
B. Sediment ✓ Correct
C. Husk
D. Vapour
Solution: The solid that settles at the bottom during sedimentation is called the sediment.
Q11 — Sedimentation & Decantation · easy · theory
Gently pouring off the clear liquid from the top without disturbing the settled solid is called …
A. Sieving
B. Winnowing
C. Evaporation
D. Decantation ✓ Correct
Solution: Carefully pouring away the clear upper liquid, leaving the sediment behind, is called decantation.
Q12 — Sedimentation & Decantation · easy · theory
Sedimentation and decantation together are used to separate …
A. Iron from a magnet
B. A heavier insoluble solid from a liquid, like mud from water ✓ Correct
C. Salt dissolved in water
D. Two gases
Solution: They are used to separate a heavier insoluble solid, such as mud, from a liquid such as water.
Q13 — Magnetic Separation & Distillation · easy · theory
A magnet can be used to separate …
A. Iron pieces from a mixture ✓ Correct
B. Sugar from tea
C. Salt dissolved in water
D. Two gases
Solution: A magnet attracts iron, so it can pull iron pieces out of a mixture. This is magnetic separation.
Q14 — Magnetic Separation & Distillation · easy · theory
Which of these will a magnet attract?
A. A glass marble
B. An iron nail ✓ Correct
C. A wooden block
D. A plastic spoon
Solution: Iron is a magnetic material, so a magnet attracts the iron nail but not plastic, glass or wood.
Q15 — Magnetic Separation & Distillation · easy · theory
Magnetic separation is a good way to separate iron filings from …
A. A heap of sand ✓ Correct
B. Boiling water
C. Salt water
D. Two mixed gases
Solution: A magnet picks up the iron filings while the sand is left behind, cleanly separating the two.
Q16 — Magnetic Separation & Distillation · easy · theory
Which of these materials is NOT attracted by a magnet?
A. Steel
B. Nickel
C. Iron
D. Plastic ✓ Correct
Solution: Iron, steel and nickel are magnetic, but plastic is not attracted by a magnet.
Q17 — Filtration & Evaporation · hard · theory
Sea water is let into shallow pans and left in the hot sun until dry salt is left behind. Which method is this?
A. Winnowing
B. Evaporation ✓ Correct
C. Magnetic separation
D. Filtration
Solution: The sun heats the sea water so the water slowly turns into vapour and escapes, leaving salt behind. This is evaporation.
Q18 — Filtration & Evaporation · hard · theory
A mixture of chalk powder and water is shaken well. Chalk does not dissolve. The best way to separate the chalk is …
A. Evaporation
B. Sieving
C. Filtration ✓ Correct
D. Winnowing
Solution: Chalk is an insoluble solid that stays as tiny bits in the water, so it can be caught on filter paper by filtration.
Q19 — Winnowing & Sieving · hard · theory
Sieving can separate a mixture only when its parts are of …
A. Different sizes ✓ Correct
B. Different colours
C. The same size
D. The same weight
Solution: A sieve separates by size, so it works only when the pieces in the mixture are of clearly different sizes.
Q20 — Winnowing & Sieving · hard · theory
Which pair of things can be separated by winnowing?
A. Iron filings and sulphur
B. Husk and grain ✓ Correct
C. Sand and water
D. Sugar and salt
Solution: Winnowing needs one part to be much lighter than the other so the wind can blow it away; husk (light) and grain (heavy) fit this.
Q21 — Sedimentation & Decantation · hard · theory
To make muddy river water settle faster, people sometimes add a pinch of alum (fitkari). The alum …
A. Turns the mud into salt
B. Dissolves the mud completely
C. Makes the mud settle to the bottom faster ✓ Correct
D. Makes the water boil
Solution: Alum makes the fine mud particles clump together and settle faster, speeding up sedimentation.
Q22 — Sedimentation & Decantation · hard · theory
After decanting muddy water, some fine mud still floats in it. To make the water fully clear, we should next use …
A. Filtration ✓ Correct
B. Winnowing
C. Evaporation
D. A magnet
Solution: The tiny mud bits left after decantation can be caught on filter paper, so filtration is used to make the water fully clear.
Q23 — Magnetic Separation & Distillation · hard · theory
To get pure drinking water from salty sea water, the best method is …
A. Winnowing
B. Simple evaporation
C. Distillation ✓ Correct
D. Magnetic separation
Solution: Distillation removes the salt AND gives back clean liquid water, so it is the best way to get pure water from sea water.
Q24 — Magnetic Separation & Distillation · hard · theory
A magnet cannot separate a mixture of sand and sugar because …
A. Sand and sugar are both too heavy
B. Neither sand nor sugar is attracted by a magnet ✓ Correct
C. The magnet is too small
D. Sugar dissolves in the magnet
Solution: A magnet only attracts magnetic materials like iron; since neither sand nor sugar is magnetic, a magnet cannot separate them.
Q25 — Filtration & Evaporation · medium · theory
To get salt back from a bowl of salt water, we use …
A. A magnet
B. Sieving
C. Filtration
D. Evaporation ✓ Correct
Solution: Salt is dissolved in the water, so on heating the water evaporates and the salt is left behind. This is evaporation.
Q26 — Filtration & Evaporation · medium · theory
During evaporation of salt water, the water …
A. Stays in the bowl and the salt escapes
B. Passes through a filter paper
C. Turns into vapour and escapes, leaving the salt behind ✓ Correct
D. Turns into salt
Solution: On heating, the water changes into vapour and escapes into the air, while the solid salt is left behind in the bowl.
Q27 — Filtration & Evaporation · medium · numerical
100 g of salt water is heated until all the water evaporates, leaving 8 g of salt. How much water evaporated?
A. 108 g
B. 92 g ✓ Correct
C. 8 g
D. 100 g
Solution: Water evaporated = total mixture − salt left = 100 − 8 = 92 g.
Q28 — Filtration & Evaporation · medium · theory
Why can we NOT separate salt from salt water by filtration?
A. Salt is magnetic
B. Filter paper does not let water through
C. Salt is dissolved, so it passes through the filter paper with the water ✓ Correct
D. Salt is too heavy for the filter paper
Solution: Dissolved salt passes through the filter paper along with the water, so filtration cannot separate it; evaporation is needed.
Q29 — Winnowing & Sieving · medium · theory
A farmer drops a mixture of grain and husk from a height while the wind blows. Where does the lighter husk land?
A. Farther away, carried by the wind ✓ Correct
B. It sinks into the ground
C. It rises up into the sky forever
D. Straight below, with the grain
Solution: Being lighter, the husk is carried farther away by the wind, while the heavier grain falls straight down in a heap.
Q30 — Winnowing & Sieving · medium · theory
Which of these is best separated by sieving?
A. Iron nails from a heap of sand
B. Salt dissolved in water
C. Small stones mixed in wheat flour ✓ Correct
D. Oil floating on water
Solution: The stones and flour are of different sizes, so a sieve lets the fine flour pass and keeps the larger stones back.