Diffusion Lab Report

Lab Report

Diffusion is
- One of two kinds of passive transport,
- Diffusion can transport ions from higher concentration to lower concentration region without any other forces.
- A net movement of molecules in and out of cell membrane
- Diffusion can be affected by the steepness of the concentration gradient.

Lab question:
Is the rate of diffusion influenced by the presence of second molecule?

Prediction: the rate of diffusion is influenced by the presence of second molecule.

Material:
- Computer
- Vernier computer interface
- Logger Pro
- Vernier Conductivity Probe
- three 18×150 mm test tubes with rack
- 1％, 5％, 10％ salt water
- 400mL beaker
- dialysis tubing, 2.5cm ×12 cm
- Dropper pipet or Beral pipet.
-
Connect the Conductivity Probe to the computer interface, and run Logger.
2. Put beaker on the Ring stand and pour 400ml water into beaker.
3. get 1%, 5%, 10% salt water in to three dialysis tubes
( -Obtain 15 mL of 1%, 5% and 10% salt-water solutions in each tube.
-Soak three dialysis tubes into beaker one by one, and tie one end of the dialysis tubes.
-Use a Beral pipet, transfer 15 mL of the 1%, 5% and 10% salt water into the dialysis tube
-Tie off the other end of tube.)
4. put a weak magnet into the bottom of beaker.
5. wait for 20 sec
6. record by logger pro for 120 sec for 3 times (1%, 5% and 10% salt water each)
7. observe and compare all the data
8. get conclusion
9. Put every thing back and trash all three-dialysis tube.

Questions:

1. The more salt concentration, the higher rate of diffusion will have.
2. my conclusion proved my prediction is right. Almost no