4.9 Post-experiment questions – Conduct any activity to
demonstrate osmosis
1. Define osmosis.
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2. In the space provided, draw a diagram of the apparatus you used to demonstrate
osmosis.
3. (a) Where was the highest water concentration in your experimental set-up?
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(b) What represented a semi-permeable membrane?
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(c) Explain what is meant by semi-permeable membrane?
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(d) Where was the highest solute concentration in your experimental set-up?
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4. a) What was the result of your experiment?
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a) What was the result of your control?
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b) State any two precautions in this experiment.
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5. (a) An animal cell is immersed in pure water. What will happen and give a reason
why?
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(b) How does Amoeba living in fresh water overcome this problem?
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(c) In the spaces below, draw diagrams of red blood cells after they have been
placed
in:
(i) distilled water and
(ii) strong salt
solution
(d) What is osmoregulation?
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6. (a) What surrounds a plant cell membrane?
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(b) In the space below, draw labelled diagrams to show a plant cell after is has
been placed in (i) distilled water and (ii) strong salt solution.
(c) How do plants make use of pure water?
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(d) When a plant wilts, what has happened to its cells?
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7. (a) Explain how adding salt or sugar can preserve food.
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(b) State an example of food that is preserved using:
(i) Salt: _________________________i) Sugar: ________________________
(c) Osmosis is a passive process. Explain.
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(d) In what way can osmosis be considered a special case of diffusion?
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(e) How would you demonstrate that osmosis only occurs in a living cell?
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(f) What is the purpose of visking tubing?
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(g) If a strong starch solution is placed inside visking tubing and then immersed
into a beaker of distilled water to which iodine has been added, what colour change,
if any, would you expect (i) Inside the visking tubing?
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(ii) In the beaker of distilled water?
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