osmosis. Aim: To find out in which solution (salted or pure water) the potatos cell lets more things in.

Apparatus:

• Scale
• Three 250 ml beakers
• A potato
• 75 ml of water
• 75 ml of salt solution
• Measuring cylinder
• Potato-cutter
• A stop-watch
• A napkin

Method:

1. Get all the apparatus shown above.
2. Cut 9 equal pieces (estimate) of potatoes with the potato cutter.
3. Dry them with a napkin.
4. Measure the mass of each one of them with the scale. (Record the results).
5. Label them as potato 1, potato 2, etc.
6. Fill a beaker with 50 ml of water.
7. Fill a beaker with 50 ml of salt solution.
8. Fill a beaker with the 25 ml of water and the 25 ml of salt solution.
9. Put potatoes’ 1, 2, and 3 in the beaker with pure water and start the stop-watch.
10. When the stop watch reaches 20 min take the potatoes out of the water.
11. Dry them.
12. Put potatoes’ 4, 5, and 6 in the beaker with the combined solution of water and salt and start the stop watch.
13. Repeat steps 10 and 11.
14. Put potatoes 7, 8, and 9 in the beaker with the salt solution and start the stop watch.
15. Repeat steps 10 and 11.
16. Measure the mass of each potato. (Record results).

Variables:

• Control: The number of potatoes we put on and the time we leave them there.
• Independent: the solution we put the potatoes on.
• Dependent: the weight of the potato-

Results:

Discussion: I think the results where as I predicted. Pure water absorbs more than the mixture and the solution.

Evaluation: I think my results weren’t as accurate as I hoped them to be. Much of the potatoes stayed with the same weight or even more of what they where supposed to have, and maybe this is because at the end we couldn’t dry them that much.

Conclusion: Potatoes that are in pure water absorb way much more water that potatoes in the other solutions. In salt solution some of the potatoes weight decreased.