Potato Lab.
Inquiring and Designing
Introduction:
We will be testing how the size and shape of a potato changed based on what water solution it is placed in. There will be 5 different solutions. 1. Pure water (No Sugar added) 2. 10% sugar 3. 20% sugar 4. 30% sugar 5. 40% sugar.
Research Question:
What is the effect of increasing the concentration of sugar in a sugar solution on the mass of a potato crore suspended in the sugar solution environment?
Hypothesis:
The percentage of water in a potato is between 80-98 percent, so clearly there is a lot of water in a potato. I think that the if we put more sugar in the water that we place the potato into then the smaller the potato will get because some, or most of the water will have been extracted from it. Because in higher concentration of sugar more water is needed to dissolve all of the sugar. This is Diffusion.
Variables:
Variable Type
Variable
How to measure or control this variable
Independent
Potato
We will put the cores of potato into sugar water and pure water and see how it affects it.
Dependent
Size of potato
It is clearly visible too, but we will record the weight of the cores, before and after.
Controlled
The controlled variable is the water and the amount of sugar in it.
We will tmeasure and put the right amount of sugar concentration into each cup of water, 40% 30% 20% 10 % and
I think that the if we put more sugar in the water that we place the potato into then the smaller the potato will get because some, or most of the water will have been extracted from it. Because in higher concentration of sugar more water is needed to dissolve all of the sugar. This is diffusion. According to our data my hypothesis was correct, since the potatoes did shrink in the higher concentration of sugar in water. The potato was the smallest in the 40% cup, which makes sense based on our graph and
If this experiment were designed to determine the amount of Fructose in a solution, describe what, if anything, would need to change in the reaction? Explain why there would or would not need to be changes. (5
then cut up 5 pieces of potato and weigh them to make sure they all
B will have this size potato in but cut in half and Test tube C will
The Effect of Solute Concentration on the Rate of Osmosis Aim: To test and observe how the concentration gradient between a potato and water & sugar solution will affect the rate of osmosis. Introduction: Osmosis is defined as, diffusion, or net movement, of free water molecules from high to low concentration through a semi-permeable membrane. When a substance, such as sugar (which we will be using in the experiment we are about to analyse), dissolves in water, it attracts free water molecules to itself, and in doing so, stops them from moving freely. The effect of this, is that the concentration of (free) water molecules in that environment goes down. There are less free water molecules, and therefore less water molecules to pass across a semi-permeable membrane, through which sugar molecules and other molecules attached to them are too big to diffuse across with ease.
Conclusion In my conclusion, the potatoes with the lowest concentration gained the most mass, and would become hard relating back to the Turgor theory I stated earlier. In contrast to this, the potatoes in the most concentrated solution lost the most weight thus becoming plasmolysed and limp also relating back to the background I have mentioned earlier. Evaluation In general the experiment was succesful the results were consistent and also were in accordance with the theories made at the start.. The experiment could have been improved by: · More subjects used instead of potatoes · More potatoes · Wider time ranger · Different molarities Using this variety of methods could have improved the experiemnt, however I was generally satisfied with the results of this osmosis experiement.
In my experiment, I will use an overall volume of 50 cm³ of 2moles of
So the experiment will be based upon the movement of water. The first potato chip will be placed in a zero percent solution. I believe that this will increase the mass. I believe this because the zero percent solution has a lower concentration than the cell sap inside the potato. The potato takes on the water through osmosis and the cell pushes out from inside the cell making it swell and become more rigid.
potato chips left in a sugar solution for a period of 1 hour. I will
To investigate the osmotic effect of changing the concentration of sucrose solution; distilled water, 20% sucrose solution, 40% sucrose solution, 60% sucrose solution on the change in mass of potato cylinder after 30 minutes of being in solution.
Conclusions: There is a pattern on the graph, and data table, which shows that as the concentration of the sucrose solution increases, the potato's percentage change in mass decreases.
the same brand of potato. By doing this I will make it a fair test.
Knife to cut the potato to the correct shape and size for reasons. stated in the method. Tile to not score any school surfaces. Test tubes to hold the potato and solution in. Beaker to alter solution concentration.
We then cut our potato tubes with the cork borer and cut them with the scalpel so they were the same length and weighed them. We then put one potato tube in each test tube and then added the same amount sugar solution in to each tube. The concentration of sugar solutions varied in each test tube.
4. Put each group of potato discs in one of the 6 test tubes and watch
Prediction I think that when the potato is placed in distilled water the potato mass will increase. This is because water, has, if pure, a weaker concentration than the potato, and the water molecules move in through a partially permeable membrane by osmosis. If the potato is in a high concentration salt solution, the potato mass will decrease because the potato is less concentrated than the salt solution, and the water will move through the partially permeable membrane into the stronger solution. However, if the potato mass stays the same after the experiment, this means that the water/salt solution and the potato must be of equal concentration.