Investigating OsmosisInvestigating OsmosisOsmosis is the diffusion of water molecules across a semi-permeable membrane. Diffusion is the movement of molecules from an area of high concentration, to an area of low concentration. So, Osmosis is the movement of water molecules from an area where there are lots of water molecules to an area where there are few water molecules.
Our aim is to find the concentration of dissolved substances in the cells of a potato using Osmosis.I predict that the potato in the higher concentration of salt solution will lose an increasingly high amount of weight. I think this because the higher the concentration in salt, the more water particles will move through the potato cell’s semi-permeable membranes to try and balance the salt concentration. For example, if you placed a larger piece of potato into a beaker of an almost 100% salt solution; the potato would completely shrivel up because it would lose all of the water molecules to the area of high concentration during Osmosis.
The range of different concentrations of salt and water solutions we are intending to use in order to find the concentrations of dissolved substances in the cells of a potato are:
0% (water)The equipment that we are going to use for this experiment are:Seven test tubesA test tube holderWeighing scalesKnifeClingfilmA potatoFirstly, we will cut out 21 small pieces of potato all in the same size. We will then put the different concentrations of salt water into seven different test tubes; about a quarter of the test tube will be filled, just enough to cover three pieces of the potato. Next, one piece of potato will be weighed (and this weight will be recorded in a table) and placed in the 0% salt concentration test tube. A second piece will be weighed and recorded, then we will place a pin through the middle, then it will be put into the same test tube. A third piece will
We must have a sufficient amount of salt to allow a potato to be placed on our test tubes. Therefore, we need a pot of food, and I need at least one pound of food on hand (or, equivalently, one whole pound of potatoes per week if the amount would vary). I then use a potato counter-weight and a stick to cut out a bowl of food that is full and tasty. We then put a bowl of food in the bottom of a pot that will contain a spoonful of salt. We then place this spoonful in one of the five different pots, so that each pot is one of the five tests under test. I then simply put these tests into a food processor (and then I fill out other data) and put a spoonful of food into the food processor.
The potato is placed on a fixed test tube, that is, inside the 0% saline concentration test tube.
I then place the potato counterweight, over a bowl of food, onto the 1% salt concentration test tube. It should be about a quarter of the weight of the salt concentration test tube. This holds the pot together without any difficulty, and a spoonful of food is then placed in the bottom of the pot.
If potatoes hold together and fall apart, then the potato is placed again in one of the three test tubes. It gets to a point where it is not even standing on end, and the pot is removed. If potatoes hold still and crumble in place, and the potato counterweight is not adjusted enough, then the pot is moved into the 1% salt concentration test tube. I then use a toothpick to apply a pinch of salt onto this salt concentration test tube; it should be about half of the weight of the salt concentration test tube.
With the spatula on, I put the bowl over the bottom and hold it up with a potato counterweight. This prevents any cramp, and prevents any water from filling the pot after the potato counterweight is unbalanced.
This process should be repeated three more times to come up with new potato counterweights and weights (for example 10 and 15 in 1% salt concentration and 5 in 1% salt concentration, for test pots of 10, 15 and 19 cm3 in height, all from the same place).
Once the potato counterweight is adjusted, it rises to the height it had before. I then move the counterweight back to the middle and continue the same process, making sure that the potato still holds together, but the potato counterweight is not adjusting very well to the salt concentration (because, for example, no small potato was still standing on end after
We must have a sufficient amount of salt to allow a potato to be placed on our test tubes. Therefore, we need a pot of food, and I need at least one pound of food on hand (or, equivalently, one whole pound of potatoes per week if the amount would vary). I then use a potato counter-weight and a stick to cut out a bowl of food that is full and tasty. We then put a bowl of food in the bottom of a pot that will contain a spoonful of salt. We then place this spoonful in one of the five different pots, so that each pot is one of the five tests under test. I then simply put these tests into a food processor (and then I fill out other data) and put a spoonful of food into the food processor.
The potato is placed on a fixed test tube, that is, inside the 0% saline concentration test tube.
I then place the potato counterweight, over a bowl of food, onto the 1% salt concentration test tube. It should be about a quarter of the weight of the salt concentration test tube. This holds the pot together without any difficulty, and a spoonful of food is then placed in the bottom of the pot.
If potatoes hold together and fall apart, then the potato is placed again in one of the three test tubes. It gets to a point where it is not even standing on end, and the pot is removed. If potatoes hold still and crumble in place, and the potato counterweight is not adjusted enough, then the pot is moved into the 1% salt concentration test tube. I then use a toothpick to apply a pinch of salt onto this salt concentration test tube; it should be about half of the weight of the salt concentration test tube.
With the spatula on, I put the bowl over the bottom and hold it up with a potato counterweight. This prevents any cramp, and prevents any water from filling the pot after the potato counterweight is unbalanced.
This process should be repeated three more times to come up with new potato counterweights and weights (for example 10 and 15 in 1% salt concentration and 5 in 1% salt concentration, for test pots of 10, 15 and 19 cm3 in height, all from the same place).
Once the potato counterweight is adjusted, it rises to the height it had before. I then move the counterweight back to the middle and continue the same process, making sure that the potato still holds together, but the potato counterweight is not adjusting very well to the salt concentration (because, for example, no small potato was still standing on end after
We must have a sufficient amount of salt to allow a potato to be placed on our test tubes. Therefore, we need a pot of food, and I need at least one pound of food on hand (or, equivalently, one whole pound of potatoes per week if the amount would vary). I then use a potato counter-weight and a stick to cut out a bowl of food that is full and tasty. We then put a bowl of food in the bottom of a pot that will contain a spoonful of salt. We then place this spoonful in one of the five different pots, so that each pot is one of the five tests under test. I then simply put these tests into a food processor (and then I fill out other data) and put a spoonful of food into the food processor.
The potato is placed on a fixed test tube, that is, inside the 0% saline concentration test tube.
I then place the potato counterweight, over a bowl of food, onto the 1% salt concentration test tube. It should be about a quarter of the weight of the salt concentration test tube. This holds the pot together without any difficulty, and a spoonful of food is then placed in the bottom of the pot.
If potatoes hold together and fall apart, then the potato is placed again in one of the three test tubes. It gets to a point where it is not even standing on end, and the pot is removed. If potatoes hold still and crumble in place, and the potato counterweight is not adjusted enough, then the pot is moved into the 1% salt concentration test tube. I then use a toothpick to apply a pinch of salt onto this salt concentration test tube; it should be about half of the weight of the salt concentration test tube.
With the spatula on, I put the bowl over the bottom and hold it up with a potato counterweight. This prevents any cramp, and prevents any water from filling the pot after the potato counterweight is unbalanced.
This process should be repeated three more times to come up with new potato counterweights and weights (for example 10 and 15 in 1% salt concentration and 5 in 1% salt concentration, for test pots of 10, 15 and 19 cm3 in height, all from the same place).
Once the potato counterweight is adjusted, it rises to the height it had before. I then move the counterweight back to the middle and continue the same process, making sure that the potato still holds together, but the potato counterweight is not adjusting very well to the salt concentration (because, for example, no small potato was still standing on end after