Potato Lab

By Debbie Froese, Rosemary Reimer, and Eva Neufeld

Problem

If the six solutions each contain different molarities of sucrose, how will we be able to determine the concentration by using water potential? What are the molarities of each?

Hypothesis

If the potato has a greater water potential, there is less sucrose in the solution that particular potato is contained in.

Manipulated Variable

Molarities of sucrose in the six different solutions

Range to be Used

The potato pieces will stay in the different solutions for 72 hours.

Describe how the control would be set up.

There will be peeled potato slices of equal size in each container. All six containers will contain the same amount of solution, and they will all be kept at room temperature. Each potato will be given the same amount of time for osmosis to occur.

Three constant factors used in this lab are...

-amount of solution in each container

-room temperature solution

-same size potato in each solution

Materials

-Potatoes

-Cutting Instruments

-Triple-Beam Balances

-Metric Rulers

-Cups

-Thermometers

-Color Coded Sucrose Solutions

-Plastic Wrap

Procedure

1.) Peel off the skin of a potato.

2.) Measure out six equal sized pieces of potato. Make sure they are fairly close in mass.

3.) Put equal amounts of each of the six solutions in six different containers.

4.) Place a piece of potato in each solution and cover each container with plastic wrap.

5.) Leave the covered containers sitting at room temperature over the weekend (72 hours).

6.) After 72 hours have passed, check how far the solutions have traveled.

7.) Make calculations to find water potential.

8.) Determine the molarities of each solution by using their water potentials as a guide.