Investigating the phenomenon of Osmosis in plant tissues:
Potato in different concentrations of NaCl
Tutor: Maria Tsaousidou
By Marina Gkritzioudi
Biology Lab Report 2
Investigating the phenomenon of Osmosis in plant tissues:
Potato in different concentrations of NaCl
Tutor: Maria Tsaousidou
By Marina Gkritzioudi
Investigating the phenomenon of Osmosis in plant tissues:
Potato in different concentrations of NaCl
Introduction:
Osmosis is the movement of water molecules through a semipermeable membrane from low concentration to high concentration.
Research Question:
How does the concentration of salt (NaCl) affect the mass of a potato soaked in water (H2O) with different concentrations of NaCl over the course of 30 minutes?
Hypothesis:
It is expected that the solution with the highest concentration of salt will cause more mass loss to the pieces of potato. The pieces that will be placed in the solution with the lowest concentration of salt will have small weight loss. Finally, the pieces that will be placed in water (NaCl concentration 0) will gain weight. This is expected because of the phenomenon of osmosis which was examined in a previous lab.
Variables:
Independent: concentration (%) of salt (NaCl) Dependent: mass (g) change
Controlled:
* shape and material of the beakers * size and weight of the potato pieces * volume of the aqueous solution
The beakers need to be of the same size, of the same shape and of the same material, either plastic or glass. The size of the potato pieces needs to be the same in order for the surface to volume ratio to be the same and the initial weight of the pieces should also be the same so that the mass change can be compared. Since this is not always possible, we calculate percentages and make the pieces approximately the same. Lastly, the volume of the water solutions should be the same in all beakers so that the osmotic effect will only depend on the