Skip to main content
Medicine LibreTexts

Diffusion and Osmosis II (Worksheet)

  • Page ID
    3550
  • Name: ______________________________

    Section: _____________________________

    Student ID#:__________________________

    Work in groups on these problems. You should try to answer the questions without referring to your textbook. If you get stuck, try asking another group for help.

    1. Circle the correct answer.

    a) When red blood cells are placed in an isotonic solution they:
    swell / stay the same / shrink.
    b) Red blood cells are isotonic to:
    distilled water / 0.2% salt solution / 0.9% salt solution / 2.0% salt solution.
    c) Red blood cells placed in a 2.0% salts solution would:
    swell / stay the same / shrink.
    d) Red blood cells placed in distilled water would:
    swell / stay the same / shrink.
    e) When red blood cells are placed in distilled water:
    the water enters the cells / the water leaves the cells / the water does not move / the salts in the cells leave the cells
    f) Red blood cells placed in a 0.9% salt solution would:
    swell / stay the same / shrink.
    g) Red blood cells placed in distilled water are in a:
    hypertonic / isotonic / hypotonic solution.
    h) Red blood cells placed in 0.9% salt solution are in a:
    hypotonic / isotonic / hypertonic solution.
    i) Red blood cells placed in a 2.0% salt solution are in a:
    hypotonic / isotonic / 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:
    swell / stay the same / 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? A B C
    ii) Which bottle contains water? A B C
    iii) Which bottle contains the isotonic salt solution? A B C
    iv) Which bottle contains the hypotonic solution? A B C
    v) Which bottle contains the hypertonic salt solution A B C

    3. Now try this one!

    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


    Circle the correct answer in the statements below.

    (Note that salt has quite a small molecule, glucose has a moderate sized molecule and albumin is a protein with a very large sized molecule.)

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