The aim of the experiment was to determine the osmolarity of the potato. In the experiment, the % mass change increased from -4.2% to 6.5% and drops to -16%. In 1%, 4% and 5% concentrations, the potato showed up as hypertonic and 2% and 3% concentrations are hypotonic. The standard deviation of concentration 3% showed up as 8, which is extremely high. It shows that the experiment of the concentration 3% was not accurate. Percentage uncertainty, which equal to the random error, was 1.33133%. The expected result was that the % mass change will decrease gradually from positive percentage to negative percentage (hypotonic to hypertonic), and the osmolarity of the potato could be calculate by using the moment when the graph and 0% mass change intersects. But in the result, the graph starts with negative percentage, increased to positive …show more content…
In the graph, it is hard to estimate the osmolarity of the potato. Based on the best fit linear graph, the moment when there is no osmosis is when the concentration of the walt water is 1.89%, but it is not reliable because the graph moves up and down. It is hard to say whether the experiment was correct or not because there are no theoretical value or literature value to compare with the result. But since the osmolarity of the potato is constant, it is impossible to start the graph with hypertonic. It should start with hypotonic and moves to hypertonic as the concentration of the salt water increases. There are few reasons why the result of the experiment is not reliable. First of all, the standard deviation of the % mass change is so big, which means the experiment was not accurate. According to the Table 3, the % mass change of 3% concentration increases to 18% and decreases to -11%. As each trial shows the big difference each other, the experiment is not reliable. Not only 3% concentration, 2% and 4% concentration shows big difference
This means that there are more collisions between the solid and liquid. Amount of tap water H2O used, i.e. volume (in ml) of the syringe. Amount of Alka-Seltzer tablets used, i.e. quantity of the tablets. one is used for the. Number of times the solution is stirred.
The first thing I needed to see was how different concentrations affected the weight and length of the potato. So I needed to see each extreme - highest concentration and lowest concentration. I used 0 molar concentrations (the lowest) and 1 molar (the highest.) I then left each test for 20 minutes, but found after that time a slight reaction had taken place - the potato chips only increased or decreased by a very short amount. I then predicted that now I would have to leave the tests for a longer amount of time and use longer potato chips to ensure that there is enough of a reaction to compare
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.
The purpose of this experiment is to investigate the effect of changing the concentration of sodium chloride solution on the rate of osmosis in tubes of potatoes. This was maintained using equal measurements of the potato tubes and applying them into the different concentrations of sodium chloride, 0%, 2%, 5%, 10%, 20% and 26%, in beakers then measuring the change in mass of the potato tubes afterwards. The time taken for all potato tubes to be placed in solution was 15 minutes. Can the concentration gradient of the sodium chloride solution influence on the rate of osmotic diffusion undergone by the potato tubes?
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
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.
When doing this experiment I was able to see the effect of different concentrations on the rate of osmosis, each was done by measuring the initial mass and length of the potato cylinder and after osmosis, the results were conducted to show that as the sucrose concentration increases the rate of osmosis also increases as I said in my hypothesis thusly making a direct decrease in mass.
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.
Diagram:.. Variables:.. I am making variables in only one field. I am changing only the concentration of the salt solution.
Investigating the Effect of Sugar Solution on the Weight and Size of Potato Cells Aim: To investigate whether the different concentration of sugar solution will affect the weight and size of the potato cells. General background information: Osmosis is defined as the movement of water or any other solution's molecules from an area in which they are highly concentrated to a region in which they are less concentrated. This movement must take place across a partially permeable membrane such as a cell wall, which lets smaller molecules (E.g. water) through but does not allow larger solute molecules to pass through. The molecules will continue to diffuse until the area in which the molecules are found to reach a state of equilibrium, meaning that the molecules are equally distributed throughout the cell, with no area having a higher or lower concentration than any other hence equal. Hypothesis/prediction: For this particular investigation I believe that the lower the concentration of the sugar solution in the test tube the mass of the potato will be greater and the longer the potato cells will be.
There is also the potential of human error within this experiment for example finding the meniscus is important to get an accurate amount using the graduated pipettes and burettes. There is a possibility that at one point in the experiment a chemical was measured inaccurately affecting the results. To resolve this, the experiment should have been repeated three times.
Osmosis in Potato Tubes Osmosis: Osmosis is the movement of water molecules through a semi-permeable membrane from a high concentration to a low concentration. Diagram: [IMAGE] [IMAGE] Aim: To see the effects of different concentration of sugar solution on Osmosis in potato tubes. Key factor: In the investigation we change the sugar solution from: 0%-10%-20%-30%-40%-50% this is the independent variable; the dependant variable is the change in mass. Prediction: I predict that all the potato tubes in pure water or low concentration sugar solution will swell because water enters their cells by osmosis.
The Effect of Water Concentration on the Mass of Potato Tissue Aim: The aim of this investigation is to discover the effect of water concentration on the mass of potato tissue, and also to investigate the movement of osmosis through potato tissue. Scientific Knowledge: When a substance such as a sugar dissolves in water, the sugar molecules attract some of the water molecules and stop them moving freely. This, in effect, reduces the concentration of water molecules.
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.