The Effect of Concentration on Osmosis
We will be conducting an experiment to investigate the effect of
different concentrations of salt solutions on osmosis.
I predict that "In the plant tissue, there will be a certain salt
concentration. Although we are not sure of what it is, I predict that
if the concentration is lower than that in the potato, the potato will
increase in size and mass. If the concentration is higher than that in
the potato, the potato will decrease in size and mass. If it only
increases or only decreases the percentage of change which is the
lowest will be that closest to the concentration in the potato."
The cell membrane on the outside of the potato cells is a partially
permeable membrane. This means it will only let certain molecules pass
through it. The molecules it lets through are water molecules. Which
way it lets them through depends on the concentration on either side
of the membrane. As I already said we do not know the amount of salt
solution in the potato. If the concentration outside the potato is
higher than inside, the water molecules will diffuse out through the
potato cell membrane. That explains why I think the mass and size of
the will decrease in a high concentration solution. This also explains
why I think it will increase when it is put in a less concentrated
solution, because the water will diffuse into the potato, therefore
increasing its mass and size.
[IMAGE][IMAGE]
Apparatus I will use will be: Test tubes, test tube holder, potato, 2M
sodium chloride solution, distilled water, cork borer, knife, ruler,
electronic balance.
We will have 10 test tubes, and each one will have a 2cm piece of
potato in it. We will make up the following solutions using distilled
water and 2m sodium chloride solution; 1.5M, 1M, 0.5M, 0.25M. In order
to make these we worked out the ratio of 2M solution needed to the
amount of distilled water needed to make up that concentration. We
will pour 10ml into each of the test tubes.
5. A second test tube was then filled with water and placed in a test
We then took 1ml of the 0.1% solution from test tube 2 using the glucose pipette and added it to test tube 3, we then used the H2O pipette and added 9ml of H2O into test tube 3 creating 10ml of 0.01% solution.
Test tube A will have a piece of potato which is this size. Test tube
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.
Osmosis Experiment Planning Aim: The main subject that I will be planning to investigate is the effects of a concentrated sucrose solution on potato cells on the basis of the Osmosis theory. Background knowledge: The plant cell and its structure To understand osmosis in detail I will need to explain the plant cell (which is the cell included in the osmosis experiment) and its cell membrane. Below I have a diagram of a plant cell: [IMAGE] Osmosis is about the movement of particles from a higher concentrated solution to a lower concentrated solution to create an ethical balance via a partially or semi permeable cell membrane. Osmosis in simple terms is the exchange of particles between the cytoplasm inside the cell and the solution outside the cell. What makes this exhange is the partially permable cell membrane.
* In the first dialysis tube (bag A), we would insert ten mL of one
Osmosis is a type of diffusion which is only applied on water and is a passive process which does not require an input of energy from the cell; this is because materials are moving with the concentration gradient. Osmosis is a process that occurs at a cellular level, which entails the spontaneous net movement of water through a selectively permeable membrane, from a region of high to low water concentration, in order to equalise the level of water in each region. This form of diffusion takes place when the molecules in a high concentration are too large to move through the membrane. The term semi-permeable or selectively permeable means that some substances can easily pass through the cell membrane, whereas others cannot. The significance of osmosis to cells is great, since it is the osmotic pressure that maintains the shape of an animal cell and provides support in the plant cells. Many factors affect the rate of osmosis including size of particles and temperature however in this particular experiment the factor investigated is the concentration of sodium chloride. Tubes of potatoes will be used to demonstrate the fact...
molecules go in and out of the cell. There is no net movement of water
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.
If the concentration of sucrose increases, then the mass of the potato will decrease. However, if the concentration of the solution in the beaker is less than that of the potato (such as distilled water), then the mass of the potato will increase. So, as the concentration of sucrose increases the rate of osmosis increases.
Put a label on each test tube. With a pencil, number each test tube from one to twelve.
- The nurse’s mistake will increase the saltiness due to the double amount of saline in the bag.
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
when to do it etc. This should lead me to good results at the end of
tube. Add 6 mL of 0.1M HCl to the first test tube, then 0.1M KMnO4 and