Tutorial #1
1) a) Density: Density is a physical property and is a measure of how heavy an object is in a given volume. It is also defined as mass per volume. It is expressed in g/ml or g/L. Example would be oil and water. Oil floats on water because it has less density.
b) Solvent: Solvent is a liquid in which substances are dissolved to form a solution. Example is sugar and water. In this case, water is a solvent and sugar is a substance (solute).
c) Amphipathic: A molecule that has a polar and non polar region. Polar being water soluble and have charges (+ve or –ve) whereas non polar being not water soluble and lack charges. A phospholipid molecule is an example of amphipathic.
d) Hydrophobic: Generally hydrophobia means fear of water. It means that certain substances have the inability to dissolve in water. Again an example would be oil in water.
2) a)
3) a) The properties are called Colligative Properties.
b) Four properties that depend upon effective particle concentration are freezing point, boiling point, water vapor pressure of a solution and osmotic pressure.
4)

.85 concentration is closest to that of plasma (290 mOsm/Kg).
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8) a) 1) When the red blood cell is placed in a fresh water, it would burst and swell because water molecules would enter into the cell.
2) When the red blood cell is placed in a salt solution at a concentration of 300mOsm, it would not change and no effect.
3) When the red blood cell is placed in a salt solution at a concentration of 400mOsm, it will burst and swell because water molecules would enter into the cell.
4) When a red blood cell is placed in a urea solution at a concentration of 400mOsm, the cell would swell and burst.
b) A salt solution at a concentration of 400mOsm and a urea solution at a concentration of 400mOsm were isosmotic to the red blood cells.
c) A salt solution at a concentration