Osmosis Investigation
Aim
What happens to the mass of a raisin when you put it onto different
sugar solutions?
A sugar solution is made from glucose and water. A raisin is a dried
grape. A sugar solution is inside a grape.
Prediction
In a weaker sugar solution the water goes in, so the mass increases.
In a stronger sugar solution the water goes out, so the mass
decreases. In a weaker sugar solution the raisin’s mass increase
caused by osmosis, the particles are absorbed by the raisin. In a
stronger sugar solution the raisin’s mass decreases, also caused by
osmosis, as the solution already inside the raisin comes out.
This raisin has gained water by osmosis.
This raisin has lost water by osmosis.
Method
- Set up equipment.
- Put one raisin in each beaker. One with a weak solution, one with a
strong solution.
- Measure the mass of the raisins every 5 minutes for 30 minutes.
- Record results in a table.
Equipment
2 beakers – to contain the raisins and the solutions.
Scales – to measure the raisins and the sugar’s mass.
Stopwatch – to measure the time taken.
Tweezers – to pick up the raisins.
I need to take the following safety precautions:
- Don’t use fingers to pick up raisins.
- Keep an eye on the beakers.
- Don’t run with experiments.
I will make it a fair test by putting the same amount of sugar
solution in each beaker and the times recorded will be the same.
Results
First set of results
Mass of raisin before (g)
Mass of raisin after 10 mins (g)
Concentration of sugar solution (%)
Sugar (g)
0.40
0.40
0
0
0.45
0.49
5
5
0.48
0.48
10
10
0.40
0.39
15
15
Considering the fact that Marc has both been sweating and drinking minimal amounts of water, Marc is now dehydrated. This means he has less than the required amount of water for his body to complete the processes necessary to maintain its health. As stated in the question, the process of sweating causes the loss of more water than solutes. This means that as the level of water decreases, the level of solute concentration will increase, creating a change in the water to solute ratio.
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.
* We would have to leave one end open to fill it up with the different
This occurrence can be explained through the process of osmosis. The increase in mass as well as the increase in turgidity, in the potato tubes immersed in low sodium chloride concentration solutions is understood to be a hypertonic. Since the solution is hypertonic, the water molecules will diffuse into the area of lower water concentration (the potato tube) in order to achieve equilibrium. Alternatively, the decrease in mass in the potato tube submerged in highly concentrated sodium chloride solutions can be explained by its immersion in a hypotonic solution. As sodium chloride solution is less concentrated in water molecules than the potato tubes, the decrease in mass and loss of turgidity results from the net movement of water leaving the potato tube, which is higher in osmotic pressure, and diffusing into the solution.
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
We cut three potato chips to an equal length and then we set up 3
Osmosis is the facilitated diffusion of water across the cell membrane of a cell. The inside layer of the cell membrane is hydrophilic, meaning water cannot easily pass through the membrane. The cell membrane has to have aquaporins, which are water channel proteins, that move the water across the membrane. If there is a water and salt solution outside the cell, the salt can enter the cell by diffusion, but the cell membrane is not permeable to the water. Because there is more solute solution inside the cell, there is less water. The aquaporins move the water across the membrane until equilibrium is reached.
The Functions of Osmosis Osmosis is the passive transport of water through a selectively permeable membrane, a membrane that allows certain needed particles to pass through it more easily than others. Pores in this type of membrane are large enough for water to pass effortlessly through it. The flow of water during osmosis depends on the concentration of a solute either within a cell membrane or surrounding the membrane. Water naturally flows from a hypertonic solution, an area of high concentration of solute, to a hypotonic district, a solution containing a lower concentration of solute.
To carry out the Osmosis project we have to measure the amount of water and solution that enters carrot tissue through the partially permeable membrane. We will change the strengths of the solution and then weigh the carrots to see if they are heavier and have absorbed more water and solution. We can change the strengths of the solution by adding water to the solution to weaken it meaning the more water the weaker the solution. We will record our results and then repeat the experiment to make sure the results are correct and accurate. I will put different strengths of solution into five beakers and then put five equally cut carrots into the solutions.
Osmosis Introduction Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. The aim of the investigation is to find the variables that affect the rate of osmosis and how they affect the rate of reaction. The variables that affect the rate of reaction of osmosis are, · The surface area of the object, · The concentration of the solution, · Temperature of the experiment Surface area If the surface area of the object is larger then more molecules can pass through the semi-permeable membrane. This will ultimately increase the rate of reaction. [IMAGE] [IMAGE] [IMAGE][IMAGE] Small surface area Large surface area Concentration
the mass of the potato cylinder as well as the length as the mass can
Osmosis is a physical phenomenon that has been studied by scientists of various disciplines of science and engineering. Osmosis is a natural equilibrium process and forward osmosis is one of many types of osmosis processes. It works by having two solutions with different concentrations separated by a selectively permeable membrane and ‘pure’ water flows from less concentrated solution across the membrane to dilute the more concentrated solution, leaving the salts behind. The clue in the potential applications is widely used in nature, however only recently that its potential has begun to be recognised industrially and with the progress in membrane and draw solutes science in the last few decades, the research and industrialization of engineered applications of osmosis has been increased exponentially. Osmosis, or currently referred to as forward osmosis, has new applications in separation processes for wastewater treatment and seawater or brackish water desalination. Other areas of forward osmosis research
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.