Osmosis Experiment On Potatoes 5d2g6i

Osmosis Experiment On Potatoes By: Angelina Sutanto Bolang

Introduction

Osmosis is simply the movement of molecules through a semipermeable membrane from a higher concentration of water to a lower concentration of water. Osmosis can be performed in real life only with a few materials and an experiment that can be easily done. This experiment can be done with water, potatoes, beakers, salt, scale, knife, graduated cylinder and a stirring rod. When two pieces of potato is dropped into beakers, one filled with fresh water and the other filled with salt water, the potato will have changes in size. The potato in the salt water will decrease its size and the potato in the fresh water will enlarge. Why? Potatoes contain water inside of it, which makes the potato inside the salt water is hypertonic and the salt water is hypotonic. The salt water is hypotonic because when water is mixed with salt, the components are not only h20 anymore but it becomes h20 and Na+ (salt). This means there are less h2o in the salt water than the amount of h2o in the potato. Meanwhile, the potato in the fresh water is hypotonic and the water itself is hypertonic because there water is purely just contains h2o. The h2o in the potato in salt water would want to leave because there are less h2o outside causing the potato to shrink. Different than the potato in the freshwater, the h2o from the fresh water would want to go inside the potato causing the potato to enlarge.

Procedure

Materials: -

2 Beakers 300 ml of Water 5 teaspoons of Salt A Potato Stirring Rod Timer Scale Graduated Cylinder Knife

 

Independent Variable: Potato & Water. Dependent Variable: Salt.

1. 2. 3. 4. 5. 6. 7.

Using a knife cut the potato into ¼. Scale the potato and make sure two pieces are the same weight. Measure 150 ml of water using a graduated cylinder. Pour 150 ml of water into each beaker. Pour 5 teaspoons of salt into one of the beakers and mix with a stirring rod. Set timer for 1 hour without starting it yet. Place a potato into each beaker at once and start the timer as soon as the potato

hits the water. 8. After an hour, drain the water back into the graduated cylinder and measure the water. Do this step for both freshwater and salt water separately. 9. Scale the potato separately after the water has been drained. 10. Analyze the differences that happened to the potato and the water.

Data Table Before

Salt Water Mass of potato: 4g

Fresh Water Mass of potato: 4g

After

Amount of water: 150 ml Mass of potato: 2g

Amount of water: 150 ml Mass of potato: 3.5g

Amount of water: 168 ml

Amount of water: 148 ml

The biggest changes happened with the salt water solution. The potato in the salt water lost 2g of weight and the quantity of the water increased by 18 ml. Meanwhile, the potato in the fresh water decreased its weight by 0.5 g. The water also decreased by 2 ml. Although, the changes in the fresh water wasn’t as noticeable as the salt water.

Results One part of the hypothesis has been proven that the potato in salt water did shrunk by 2g because the h2o from inside went outside. It was predicted that the potato in fresh water is going to enlarge by size. The potato in the fresh water had a decreased in weight by 0.5g. Although the changes in the amount of water after the experiment was not predicted in the hypothesis. The salt water increased by 18 ml and the fresh water decreased by 2 ml.

It can be concluded that the potatoes has changed in sizes because the water form it went outside. Although, the potato in the fresh water didn’t really change a lot in size because both the fresh water and the potato contains a large amount of h2o, which makes the h2o cycling going in and out. Different form the potato in the salt water. When the two potatoes were compared side by side, there were a major difference in of size and texture. The potato from the fresh water felt a lot denser and did not feel that much of a difference as before. Although, the potato from the salt water felt softer and smoother. The experiment shows how osmosis can be interpreted with stuff around use, for example a potato.