Aim: The aim of the experiment is to show how varying the
concentration of sucrose solution affects osmosis by changing different molar solutions of sucrose and water and how it affects the potato.
Introduction: In this investigation I will be exploring the effect of varying concentration of sucrose sugar solution on the amount of activity between the solution and the potatoes.
Osmosis is the movement of water molecules across a partially permeable membrane from a high water concentration to a low water concentration.
Osmosis can be effected different things such as:
- Temperature - The warmer the solution, the quicker the osmosis will go. This is because the water molecules will be moving more quickly.
- Difference in concentrations - This will speed up the rate of osmosis because there will be more particles that'll have to change places.
- Surface Area - This will speed up the rate of osmosis because there will be more space on the potato for osmosis to take place.
- Concentration of water in potato - the higher the concentration of water in the potato the quicker osmosis will happen because less water will have to diffuse into the potato to even the amounts of water inside and outside the potato.
So Osmosis is basically a special kind of diffusion involving water molecules, which occurs when two solutions are separated by a partially permeable membrane. The water diffuses from the weaker solution to the stronger solution. Tiny holes in the membrane allow small water molecules to pass through, but the glucose molecules are too large to pass through the semi- permeable membrane.
Prediction: I predict that as I increase the concentration of sucrose high or low, the amount of water moving in or out the potato will change. Sucrose or distilled water will make the potato increase in length and mass. Water will move into the concentrated potato's cell because of the high concentration. In very little concentrated sucrose solution, water will move out of the potato and into the sucrose solution, so I predict that the length and mass of this potato will go down.
Method: first I will need:
· Cutting tile - to cut the potato on.
· Knife - to cut the potato.
· Measuring cylinder - to measure the solutions.
· Distilled water - part of the experiment.
· Sucrose - part of the experiment.
· Potatoes - part of the experiment.
· Tissue - to dry the potatoes before and after the osmosis takes place.
· Electric Balance - to weigh the potatoes accurately.
· Borer - to take out a long piece of potato.
I'll start by using the borer to take out the potatoes, then cutting it to 3cm long for each one, then weighing because this is one of the most important part of the experiment to see how the effect of osmosis change the weight of the potatoes.
I'll then collect 5 dishes where I'll put all different solutions into each one to see how the osmosis works. Here is a list of the different solution I used:
Solution No. 5
20ml of sucrose + 0ml of water
15ml of sucrose + 5ml of water
10ml of sucrose + 10ml of water
5ml of sucrose + 15ml of water
0ml of sucrose + 20ml of water
Then after I have put to solution and the potatoes in I'll keep it there for at least 45 minutes so it would show a great amount of change.
To make this experiment a fair test, I'll make sure all the pieces of potato are the same length, I'll make sure the amount of solution in each solution are the same volume, and I will make sure the temperature where it is kept is always the same so some of the solution don't get evaporate. I will not be able to maintain the temperature all the time but I will be able to make sure the length of the potatoes and the amount of solution will be the same.
Result: After the 45...