# Effect of Different Concentrations of Salt on Potato Cell Mass

1461 Words6 Pages
Aim
To investigate the effects of increasing salinity on potato cell mass.
Background Information
This experiment is based upon osmosis. Osmosis can be defined as the net movement of water molecules from a region with high concentration to a region with low concentration. This movement must take place across a partially permeable membrane such as a cell wall, which lets smaller molecules such as water through but does not allow bigger molecules to pass through. This process will take place until it reaches the equilibrium state, which means that the water molecules will be distributed until there are no regions with high or low concentrations.
Plant cells have a protective layer—called cell wall—covering its cell
Method
1) Using a sharp knife, cut the potato into thick slices. Using a ruler, cut the potato slices into 3 strips with 3cm in length with a similar width.
2) Add 3 potato strips to the petri dishes.
3) Measure the mass of the potato strips using an electronic balance (don’t forget to ‘zero’ the scale!) and record the data on a table.
4) Measure 20mL of water into each beaker. Add a spatula of refined salt; two spatulas of refined salt; three spatulas of refined salt; and four spatulas of refined salt into the beakers respectively. Stir the beakers.
5) Place in 3 potato strips into each beaker. Ensure that they are fully submerged in the solution.
6) Once all potato strips are submerged, immediately start the stopwatch. Whilst waiting, have 5 sheets of towel spread apart on the table.
7) After 5 minutes, take out the potato strips one beaker at a time and remove any excess liquid.
8) Measure the mass again and record it.
9) Repeat the steps 1-8 again and find an average value. This is done so that the amount of random errors is reduced.

Results
Table 2.0 – Table to record the change of potato cell mass
Change of Potato Cell Mass
Number of Spatulas of Salt
0 Spatula
1 Spatula
2 Spatulas
3 Spatulas
4 Spatulas
Mass before (±0.01g)
4.07
3.76
3.55
3.75
4.23
Mass after (±0.01g)
4.16
3.24
3.13
3.23
3.64

Observations
At the beginning, the potato strips were turgid, stiff as well as compact. After 5 minutes—which was the duration of