Prediction
I think the potato tubes will swell in the distilled water because there is a higher concentration in the beaker than in the potato. The potato tubes will be longer and wider.
In the 0.25 M solution, the potato tubes will swell less because it is less concentrated (in terms of water) in this beaker.
In the 0.5 M solution, the potato tubes might stay the same or shrink a little bit. This is because the concentration of water might be a little lower or of the same as that of the potato tubes.
The potato tubes will definitely shrink in the 1 M solution. The length will decrease and so will the width.
Method
- Make potato tubes out of a potato using a cork borer: two for each solution, eight in total.
- Get four little beakers and fill them with various solutions. Measure the solutions (e.g. to about 40 ml) with a measuring cylinder to make sure the values are accurate. The four different solutions are: distilled water, 0.25 M solution, 0.5 M solution and 1.0 M solution.
- Take the eight potato tubes that have just been cut out. Pair them up as each beaker needs two to go into them. For each pair, cut one of the potato tubes shorter. This is done so that we don’t confuse ourselves when we take the measurements; this way, the two potato tubes that go in each beaker are marked and we’ll know which is which.
- Either weigh the potato tubes or measure them to work out their volumes. Or both. To weigh the potato tubes, put them on a weight balance and record their masses. To work their volumes, measure the lengths and the radiuses and use the formula:
- Record the results from step 4 in a table.
- Put the potato tubes in the beakers.
- Leave them in the science lab for a day.
- The next day, pour out the solutions from the beakers first and then carefully take out the eight potato tubes.
- Either weigh or measure the potato tubes, like in step 4.
- Record the results in a table.
