Friday, 5 January 2018

Carry out the following osmosis experiment | Question 9.from Chapter 5. THE FUNDAMENTAL UNIT OF LIFE

Take four peeled potato halves and scoos each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water.
Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup D.
Keep these for two hours. Then observe the four potato cups
and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.

Answer : Water gathers in the hollowed portion of B and C due to process of Osmosis in which outside water with high concentration make a passage through a semi-permeable membrane of potato to mix with salt or sugar with low water concentration inside the potato.

(ii) Why is potato A necessary for this experiment?
Answer : Because its cells have a selectively permeable membrane, which allows or permits the entry and exit of some materials in and out of the cell using the process of Osmosis.

(iii) Explain why water does not gather in the hollowed out portions of A and D.
Answer : Water does not gather in the hollowed out portions of A and D because cup A is empty and there is no difference in concentration of water hence no osmosis will take place. Where as in in cup D, due to boiling of potato, its selectively permeable membrane has been destroyed so there will be no water accumulation due to osmosis.

This is an answered question from Chapter 5 . THE FUNDAMENTAL UNIT OF LIFE of CBSE Class 9th Science

Check for Complete Exercise Solution for Chapter 5. THE FUNDAMENTAL UNIT OF LIFE | CBSE Class 9th Science

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