Investigation to see how Concentration Affects the Rate of Osmosis on Potatoes
Planning
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The aim of this investigation is see how altering the rate the
concentration of water and salt solution affects the rate of osmosis
of potatoes.
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Osmosis is the diffusion of water from a high concentration of water
(a dilute solution) to a low concentration of water (a concentrated
solution) through a semi-permeable membrane. A semi-permeable membrane
is porous but allows water to pass through it more rapidly than
dissolved substances.
Dilute Solution
Concentrated
Solution
[IMAGE]
Movement of Water
Level of Water after Osmosis
Original level of Water
[IMAGE][IMAGE]
Semi Permeable Membrane
[IMAGE][IMAGE][IMAGE][IMAGE]
The diagram shows how water molecules have diffused from a dilute
solution to a concentrated across a semi permeable membrane. As a
result, the level of liquid on the left will rise, and fall on the
right.
The rate of osmosis is dependant on a few things. It depends on
· The thickness of the membrane
· The concentration inside and outside the membrane - Concentration
gradient
· The size of the ions
· The Surface Area.
Using potato cylinders and 1M Salt Solution (NaCl Solution). I will
look at the rate of osmosis on the potato cylinders in different
concentrations of salt solution. I will dilute the solutions using
distilled water.
Hypothesis
I predict that when the potato tubes are in a higher concentration of
the salt solution than the concentration of water, i.e. the solution
is concentrated, then the potato tubes will lose mass and become
smaller. This is because the concentration of water outside the potato
cylinders is concentrated, and there is not much water. Due to osmosis
the water inside the potato cylinders will move out. This will
decrease the mass of the potato, make it smaller and make it flaccid
due to the loss of water. The potato cells lose turgor and become
osmosis, it can works both ways so that it can pass into and out of
Investigating Osmosis In A Potato Introduction: "Osmosis is typically defines as the flow of one constituent of a solution through a membrane while the other constituents are blocked and unable to pass through the membrane. Experimentation is necessary to determine which membranes permit selective flow, or osmosis, because not all membranes act in this way. Many membranes allow all or none of the constituents of a solution to pass through; only a few allow a selective flow. In a classic demonstration of osmosis, a vertical tube containing a solution of sugar, with its lower end closed off by a semi-permeable membrane, is placed in a container of water. As the water passes through the membrane into the tube, the level of sugar solution in the tube visibly rises.
The purpose of the Tonicity lab was to help identify the effects of an isotonic, hypertonic, and hypotonic solution to a slice of potato. The difference between diffusion and osmosis is that diffusion is the movement of particles or molecules from a region of higher concentration to a region of a lower concentration. While osmosis consists of the movement of water molecules through a semipermeable from a region of high water concentration to the region of less water concentration (Major Differences). Tonicity is the ability of a solution to ?alter the internal water volume of a cell? (Difference Between Solution, 2013). An isotonic solution should keep their normal shape; the osmotic pressure outside the cell has the same pressure within the cell. A hypotonic solution, are more dilute and contain a lower concentration of nonpenetrating solutes than cells. In contrast, a hypertonic solution have a higher concentration of
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.
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.
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.
* Note the mass down in the table at the end of the first page.
When you place a potato chip in a salt or sugar solution, then if the
I am going to carry out an experiment to measure the change in mass of
Investigate the Osmosis of Potato Cells in Various Salt Solutions. Introduction I have been asked to investigate the effect of changing the concentration of a solution on the movement of water into and out of potato cells. I will be able to change the input of my experiment. The input variable is the concentration of the solution.
the same way as it does potato. I would also widen the range of sugar
The variables I could change would be the temperature of the solution. The higher the temperature of the solution the more osmosis would occur. The surface area of the potato strip, the larger the surface area the more osmosis would occur as there would be more area exposed for osmosis to take place. The concentration of the solution will affect osmosis, the higher the concentration the less osmosis would take place. The duration of the experiment also affects how much water is gained/lost by osmosis as the longer the duration is, the more osmosis would take place (osmosis would stop as soon as it reaches an equilibrium of water content inside and outside the cell.
An Experiment to Investigate Osmosis in Plant Tissue. Aim: To conduct an investigation to compare the osmotic behavior of the osmotic animal. two types of plant tissue in varying concentrations of sucrose. solution. Then we can find the solution.
water in the potato, then the water will go out of the potato and into
When I am not using them I will place them away from my experiment and