The purpose of this experiment is to calculate the mass/change in mass of plant tissue, in our case potato tubers. The change in mass of the potato tuber disk determines the osmotic concentration. After soaking the potato tubers in different concentrations of sucrose, then calculating the percent change in mass, we can determine the osmotic concentration. The…
This exercise involves estimating the osmotic concentration of potato tuber cells by using a change in mass method. The null hypothesis states that there will be no change of mass of the potato disks after they have been incubated in any sucrose solution. This means that the concentration of sucrose that the potatoes are in will no effect the movement of water in or out of the potato cells. However, the alternative hypothesis states that the mass of the potato disks will increase after they have been incubated in a hypertonic solution. The mass of the potato disks will decrease after they have been incubated in a hypertonic solution. After the results have been gathered, appropriate estimations can then be made as to what the osmotic concentrations of the potato tuber cells are. Osmotic concentrations will either be hypertonic, hypotonic or isotonic depending on the results of mass change of the potato tubers.…
The purpose of this experiment is to observe the osmosis reaction in a potato with salt and water. In cooking cooks will soak their cut potato's in water if they will not use them immediately. This allows the potato's to be used later without turning color. The experiment shows the flow of water through the membranes of the potato with salt over a period of four hours.…
As the concentration of a solute in water will, through osmosis, transfer until the concentration is nearly the same both inside the cell, or in this case potato, and outside of the cell, the potato strips both gained and lost mass due to the different concentrations of sugar in water. As expected, the potato strips placed in the concentration of sugar water closest to the concentration of sugar water in a potato had the least amount of change in mass. As the potato strips placed in substance Z and substance A both changed 7%, the concentration of sugar water in a potato must be somewhere in between a concentration of 0.4 and 0.6. One source of error for this lab is that the amount of substance placed into each Dixie cup was not measured and therefore were not consistent. If this lab were repeated, it is suggested that the amount of substance be measured in order to produce more consistent results.…
My hypothesis in this experiment was that a Yukon gold potato will naturally absorb more water than a sweet potato due to the effects of osmosis. Osmosis plays a huge role in biology for a multitude of reasons. As defined by Freeman (2012) “The movement of water is a special case of diffusion that is given its own name: osmosis, occurs only when solutions are separated by a membrane that is permeable to some molecules but not others- that is, a selectively permeable membrane.”(P.90). It is also a type of passive transport, as it does not require energy.…
Aim: In this investigation I am going to work out the sugar concentration of a potato. I aim to find this out by putting potato cores into various concentrations, measuring the mass before and after. Due to osmosis the potato cores will change in mass to make the concentrations at an isotonic level, helping us to work out the mass of the potato. I predict that potato in the weaker solutions will gain mass, because some water will be absorbed by the potato to make the concentrations isotonic. Similarly, I think the potato in the stronger solutions will lose mass as they will have to lose water to dilute the stronger solution.…
The 2nd graph was between concentration and absorbance. This is a direct relationship because as the concentration increased, the absorbance also increased. For this graph, the line should touch the origin because it is a positive slope going from lower values to higher values. Also it passes through the origin because direct variation relationships are in the form of y = mx, where y and m are constant variables. For the absorbance value to zero, the concentration must be also be zero.…
Abstract: Osmosis is a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane. In this experiment, we learn about Osmosis and Diffusion through potato cores in different concentration of sucrose, (water, .2, .4, .6, .8, 1.0). We realized that the lower the concentration, the higher the potato cores weighed.…
Aim To observe and measure the effect of osmosis on the mass of potato using a starch solution. Introduction In order to measure the effect of osmosis, eighteen pieces of potato were cut and placed in six groups, each group of three pieces cut to weigh as close as possible to one another. For each potato group, a test tube was half filled with a starch solution varying in concentration from 0% (water) to 1%. Hypothesis…
Introduction: Osmosis is the diffusion of water from a higher concentration to a lower one through a semi-permeable membrane and occurs in the cells of organisms. It is affected by the addition of solute which would lower the water potential, making water potential and solute concentration inversely related. The concept of osmosis loosely described is that the presence of more solute outside the cell means the presence of less solvent (or water molecules in this case) and vice versa; the goal of osmosis is for the water molecules inside and outside of the cell to be equal, causing equilibrium and a stop to net water movement. The goal for a recent lab was to test whether cubes of potato would gain or lose weight depending on the amount of molar concentration of sucrose they soaked in. Solutions made of different molar concentrations of the solute sucrose were prepared before this lab. Potato cubes were weighed and recorded as the initial mass in the data. Four cubes of potato were placed into 100 mL of each solution and let stand overnight. The cubes were then taken out for the final total mass to be measured and recorded. In this experiment, the potato cubes were the dependent variables, and the molar concentrations were the independent or manipulated variables.…
The aim of this experiment was to test the effect of surface area on osmosis and the effect of solute concentration on osmosis. To test this aim to hypotheses were devised. 1) If potato pieces are immersed in various salt solutions, then the pieces with the greatest surface area to volume ratio will experience the greatest weight change, because more water can move by osmosis across the potato cell’s semi permeable membrane. 2) If potato pieces are immersed in various salt solutions, then the pieces immersed in the most concentrated solution will experience he greatest weight change, because more water must pass across the potato cells semi permeable membrane by osmosis to achieve an equilibrium. The results from testing these hypotheses did not support either and were shown to be flawed because they did not reflect the theories of osmosis relating to surface area to volume ration and salt concentration.…
The main purpose of this lab is to experiment the molecular polarity on the solubility of solutes in variates of solvents and helped us to determine the polarity of the unknown solute. In this lab, we observed the effects of adding polar liquid solutes to non-polar liquid solvents. Materials used: Safety goggles 3 graduated cylinders ethanol,C2H5OH solid iodine, I2 glycerol, C3H5(OH)3 water 10 rubber stoppers 10 test tubes kerosene ammonium chloride,NH4CL an unknown solute The polarity of a solute or solvent which is present in covalent molecules illustrates which part of the molecule is either slightly positive or negative. In this lab, we experimented with different variates of solutes and observed the characteristics of the solutes when in…
Osmosis was clearly shown since the potato cylinders decreased or increased at different concentrations of sucrose. The results supported my hypothesis because for the 0.0 sucrose concentration the average percent change in mass was 16.9%. For the 0.2 concentration the percent change was 3.59%. For the 0.4 concentration the percent change was -15.3%. For the 0.6 concentration the percent change was -27.1%. For the 0.8 concentration the percent change was -23.2%. For the 1 concentration the percent change was -15.4%. The reason for the change in mass is the process of osmosis. When the sucrose concentration was 0, the cores gained weight because the concentration in the potato cells was different from the concentration outside, which was a hypertonic solution. When the sucrose concentration was 0.2, it was an isotonic solution, so there was no major difference in mass. When the concentrations of sucrose were higher (0.4, 0.6 and 0.8), the outside solution was hypotonic because there was a decrease in the potato…
Molar volume is the name given to the volume that one mole of any gas occupies at standard temperature and pressure. In chemistry, many of the materials worked with are gases. It is often easier to measure the volume of a sample of gas, rather than determine its mass. The main purpose of this lab is to determine the molar volume of hydrogen gas experimentally in order to compare it to the theoretical molar volume of ideal gases. In this experiment, a known mass of magnesium is reacted with an excess amount of hydrochloric acid to produce hydrogen gas. The amount of hydrogen gas produced is collected by the displacement of water. This volume is used to calculate the molar volume of hydrogen gas. This data can then be used to compare the experimental molar volume of hydrogen gas and that of ideal gases at STP (standard temperature and pressure), by first using the Combined Gas Law (P1V1/T1=P2V2/T2) to find the experimental molar volume at STP, followed by the Ideal Gas Law (PV=nRT) to find the molar volume of any gas at STP. The partial pressure of the hydrogen gas must be found before the combined gas law can be used. It is found using Dalton's Law of Partial Pressure (P=PH2+PH2O).…
This overall flow of water from a dilute area of high water potential to a more concentrated solution of low water potential across a partially permeable membrane is called osmosis. I predicted that the swede cylinders which are put in a test tube with a low potential of sucrose solution would become turgid because the water molecules that are present in the swede will move away from an area of higher potential of water molecules to an area that has a lower potential of water molecules, this means that the swede sample will gain mass and become full almost to an extent where it is ready to burst. The swede samples that are going to be put in a test tube with a high potential of sucrose solution will become flaccid because the swede cylinder will have a higher potential of water molecules and so these molecules will diffuse into the sucrose solution as it has a lower water potential, this means that the potato sample will shrivel and loose mass.…