Explore what happens to potatoes when you put them in a concentration of salt water and then pure water. Set up an osmosis potato lab and learn all about osmosis when you try this fun potato experiment with the kids. We are always searching for simple science experiments, which is perfect. Grab the free printable experiment below.
Potato Osmosis Lab
What is Osmosis? Learn more about osmosis through a variety of experiments.
SUPPLIES:
- Potato
- Knife
- 2 tall glasses of distilled water (or regular)
- Salt
- Tablespoon
INSTRUCTIONS:
STEP 1: Peel and then cut your potato into four equal pieces about 4 inches long and 1 inch wide.
STEP 2: Fill your glasses half way with distilled water, or regular water if no distilled is available.
STEP 3: Now mix 3 tablespoons of salt into one of the glasses and stir.
STEP 4: Place two pieces of potato into each glass and wait. Compare the potatoes after 30 minutes and then again after 12 hours.
What happened to the potato pieces? Here you can see how a potato can demonstrate the process of osmosis. Make sure to go back and read all about osmosis!
If you thought the salt water would have a higher concentration of solutes than the potato, and the distilled water would have a lower concentration you would be correct. The potato in the salt water shrinks because water moves from the potato into the more concentrated salt water.
In contrast, water moves from the less concentrated distilled water into the potato causing it to expand.
What Happens to a Potato in Salt Water?
The process of moving water across a semi-permeable membrane from a low concentrated solution to a high concentrated solution is called osmosis. A semi-permeable membrane is a thin sheet of tissue or layer of cells acting as a wall that allows only some molecules to pass through.
In plants, water enters the roots by osmosis. The plants have a higher concentration of solutes in their roots than in the soil. This causes water to move into the roots. The water then travels up the roots to the rest of the plant.
ALSO CHECK OUT: How Water Travels Through A Plant
Osmosis works in both directions. If you put a plant into water with a higher salt concentration than the concentration inside its cells, water will move out of the plant. If this happens then the plant shrinks and will eventually die.
Potatoes are a great way to demonstrate the process of osmosis in our potato osmosis experiment below. Discuss whether you think the potato or the water in each glass will have the greatest concentration of solutes (salt).
Which potato pieces do you think will expand and which will shrink in size as the water moves from a low concentration to a high concentration?
CLICK HERE TO GET YOUR FREE POTATO OSMOSIS EXPERIMENT!
More Osmosis Experiment Ideas
don’t stop with a potato osmosis lab; try one of these osmosis experiments to extend the learning.
MORE FUN EXPERIMENTS TO TRY
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