Investigating Whether the Strength of a Salt Solution Affect Osmosis in a Potato

Investigating Whether the Strength of a Salt Solution Affect Osmosis in a Potato

Factors

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Factors that could affect the experiment: -

· Temperature of water

· Type of potato

· Amount of solution

· Amount of time the potato is in the solution

Factors that I will change in my investigation: -

· Percentage of salt in solution

Preliminary Equipment

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7 Beakers (250ml)

7 strengths of sugar solution (100ml of each strength) as follows

1x 0.0% salt

1x 0.5% salt

1x 1.0% salt

1x 1.5% salt

1x 2.0% salt

1x 2.5% salt

1x 3.0% salt

Potato

Ruler

Cork Borer

Knife

Preliminary Plan

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1. Cut into potato with cork borer.

2. Measure and cut 1.5cm of potato from the cork borer. Repeat steps

1. and 2. until you have 21 pieces of potato (3 per beaker) of equal

size

3. Pour approximately 100ml of 0% salt solution into the first beaker.

Label this beaker "0%" or "Water".

4. Pour approximately 100ml of 0.5% solution into second beaker. Label

this beaker "0.5%"

5. Repeat step 4. for different solutions as follows:

a. Beaker 3 = 1.0% solution, labelled "1.0%"

b. Beaker 4 = 1.5% solution, labelled "1.5%"

c. Beaker 5 = 2.0% solution, labelled "2.0%"

d. Beaker 6 = 2.5% solution, labelled "2.5%"

e. Beaker 7 = 3.0% solution, labelled "3.0%"

6. Wait approximately 1 hour.

7. Remove potato pieces, one beaker at a time, and record the average

percentile increase or decrease of each beaker. NB. Blot each piece of

potato before measuring!

Preliminary prediction

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I predict that the cells of the potato pieces in water will become

turgid, because the water will go through the membranes in the cells,

which are semi-permeable membranes and enter the vacuole. This will

push the cytoplasm against the membrane, which will increase the