1.The motion of molecules
a. reflects the kinetic energy of molecules
b. reflect the potenital energy of molecules
c. is ordered and predictable
d. is random and erratic
2. Kinetic energy
a. is higher in larger molescules
b. is lower in larger molecules
c. increases with increasing temperature
d. decreases with increasing temperature
e. is reflected in the speed of molecular movement
3. What is the relationship between molecular size and diffusion rate?
What is the relationship between the temperature and diffusion rates?
4. The following refer to Activity 2, using dialysis sacs to study diffusion through nonliving membranes:
Sac 1: 40% glucose suspended in distille water
Did glucose pass out of the sac? Test used to determine presence of glucose:
Did the sac weight change? If so, explain the reason for its weight change:
Sac 2: 40% glucose suspended in 40% glucose
Was there net movement of glucose in either direction? Explanation:
Did the sac weight change? Explanation:
Sac 3: 10% NaCl in distilled water
Was there net movement of NaCl out of the sac?
Test used to determine the presence of NaCl:
Direction of net osmosis:
Sac 4: Sucrose and Congo red dye in distilled water
Was there net movement of dye out of the sac??
Was there net movement of sucrose out of the sac?
Explaination:
Test used to determine the movement of surcose into the beaker:
Direction of net osmosis:
5. What single characterisitics of the semipermeable membrane used in the laboratory determines the substances that can pass through them?
In addition to this characteristic, what other factors influence the passage of substances through living membranes?
6. A semipermeable sac containing 4% NaCl, 9% glucose, & 10% albumin is suspended in a solution with the following composition: 10% NaCl, 10% glucose, and 40% albumin. Assume that the sac is permeable to all substances except albumin. State whether each of the following will (a) move into the sac, (b) move into the sac, or (c) not move.
glucose water albumin NaCl
8. What is the driving force for filtration?
How does knowing this help you to explain why the filtration process examined in lab slowed down with time?
9. Define diffusion:
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