SECTION C: MOLECULAR PHENOMENA AND PRESSURE
[20 MARKS]
OUESTION C1
[5]
Answer the following questions by writing down the letter corresponding to the correct answer e.g. 1 B or 2. E, etc
1) Which of the following is the best description of a semipermeable membrane in the context of osmosis?
a) A membrane that allows neither solute nor solvent particles to pass through it.
b) A membrane that allows solute particles, but not solvent particles, to pass through it.
c) A membrane that allows solvent particles, but not solute particles, to pass through it.
d) A membrane that allows both solute and solvent particles to pass through it.
2) A cell is bathed in a solution that has a greater osmolarity than that of the cytosol. This solution is best described as one of the following.
a) Isotonic
b) Hypertonic
c) Hypotonic
d) None of the above
3) A mercury-in-glass barometer shows a height of 70 cm . What height would be shown in the barometer at the same place if water density \( 1.0 \times 10^{3} \mathrm{~kg} / \mathrm{m}^{3} \) is used? (Hint: The density of mercury is \( 13600 \mathrm{kgm}^{-3} \) ).
a) 9.52 m
b) 0.7 m
c) 0.05 m
d) 19.43 m
4) A small bubble of gas rises from the bottom of a lake. The volume of the bubble increases threefold when it reaches the surface of the lake where the atmospheric pressure is \( 1.01 \times 10^{5} \mathrm{~Pa} \). The temperature of the lake is \( 4^{\circ} \mathrm{C} \). Calculate the pressure at the bottom of the lake.
a) \( 1.01 \times 10^{5} \mathrm{~Pa} \)
b) \( 1.01 \times 10^{7} \mathrm{~Pa} \)
c) \( 3.03 \times 10^{5} \mathrm{~Pa} \)
d) \( 3.03 \times 10^{8} \mathrm{~Pa} \)
