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Medicine LibreTexts

3.17: Diffusion and Osmosis Worksheet 2 Answers

1. Circle the correct answer.

a) When red blood cells are placed in an isotonic solution they:stay the same
b) Red blood cells are isotonic to: 0.9% salt solution
c) Red blood cells placed in a 2.0% salts solution would: shrink.
d) Red blood cells placed in distilled water would: swell
e) When red blood cells are placed in distilled water: the water enters the cells
f) Red blood cells placed in a 0.9% salt solution would: stay the same
g) Red blood cells placed in distilled water are in a: hypotonic solution.
h) Red blood cells placed in 0.9% salt solution are in an:isotonic solution
i) Red blood cells placed in a 2.0% salt solution are in a:hypertonic solution.
j) A dialysis bag (made of an artificial semi-permeable membrane) filled with 0.5% salt solution and placed in a beaker containing 3.0% salt solution will: shrink.

2. Three bottles are filled with three different solutions. One with distilled water, one with 0.9% salt solution and the third with 9.0% salt solution. A few dried apricots are placed in the three bottles and left in the solutions for an hour.

The apricots in bottle A stay the same.
The apricots in bottle B shrink
The apricots in bottle C swell.

Now answer the following questions:

i) Which bottle contains the most concentrated salt solution? B
ii) Which bottle contains water? C
iii) Which bottle contains the isotonic salt solution? A
iv) Which bottle contains the hypotonic solution? C
v) Which bottle contains the hypertonic salt solution? B

3.A semi - permeable membrane (dialysis) bag, containing 4% salt, 4% glucose and 4% albumin is suspended in distilled water. Assume the bag is permeable to all substances except albumin.

Semipermeable membrane bag experiment 2.JPG

a) The saltmoves out of the bag
b) The watermoves into the bag
c) The albumindoes not move
d) The glucosemoves out of the bag
e) The salt moves by: diffusion
f) The water moves by: osmosis
g) The albumin moves by: it does not move because the molecules are too large.
h) The glucose moves by: diffusion


Ruth Lawson (Otago Polytechnic; Dunedin, New Zealand)