Sedimentation & Decantation — Homi Bhabha Class 6 Chemistry MCQs with Solutions
Free Homi Bhabha Class 6 Chemistry Sedimentation & Decantation MCQs with step-by-step solutions (10 questions). Part of Methods of Separation. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — 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.
Q2 — 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.
Q3 — 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.
Q4 — 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.
Q5 — Sedimentation & Decantation · medium · theory
In a glass of muddy water left overnight, where is the clearer water found?
A. On the sides only
B. At the top, above the settled mud ✓ Correct
C. Mixed evenly everywhere
D. At the very bottom
Solution: The mud settles at the bottom, so the clearer water is found at the top and can be decanted off.
Q6 — Sedimentation & Decantation · medium · theory
A mixture of sand and sugar is stirred into water and left to stand. What happens?
A. The sugar settles and the sand dissolves
B. Both sand and sugar settle at the bottom
C. Both dissolve and disappear
D. The sand settles, but the sugar dissolves and stays in the water ✓ Correct
Solution: Sand is insoluble and settles by sedimentation, while sugar dissolves in the water and does not settle.
Q7 — Sedimentation & Decantation · medium · theory
Why must decantation be done slowly and carefully?
A. So the water becomes magnetic
B. So the settled sediment is not disturbed and does not mix back in ✓ Correct
C. So the water does not evaporate
D. So the sediment dissolves
Solution: Pouring slowly keeps the settled sediment from being stirred up again, so only the clear liquid comes off.
Q8 — Sedimentation & Decantation · medium · theory
Sedimentation happens because the solid particles in the mixture are …
A. Lighter than the liquid
B. Made of gas
C. Dissolved in the liquid
D. Heavier than the liquid and insoluble ✓ Correct
Solution: Only heavier, insoluble particles sink and settle at the bottom; dissolved or lighter things do not settle.
Q9 — 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.
Q10 — 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.