Water can cross the membrane to reach equilibrium but salt can not. This lab uses the potato cell as the mechanism for observing fluid movement. Carrots can be substituted and also work well. The living cells work better than a static chemistry set up. Here the student must figure out why the plugs gain or loose weight.
Data collection is stressed here as well.
It is the purpose of this laboratory to observe the process of osmosis in Solanum cells. It is also the purpose to determine by calculation the exact percent of salt inside the potato cell. Use a coring device and cut 12 plugs from similar potatoes. Using a razor blade, cut the ends of each plug to remove any dry skin. The exact length is not important.