An experiment to show osmosis in potato chips in different concentrations of sucrose solution - also investigating how potato chips change in volume and weight when placed in different concentrations of sucrose solution

Authors Avatar

Factors affecting osmosis in potato tissue

Introduction:

I am going to design and modify an experiment used to show osmosis in potato chips in different concentrations of sucrose solution. I am also going to investigate on how potato chips change in volume and weight when placed in different concentrations of sucrose solution. I will also conduct a preliminary experiment before my final experiment.

Aim:

To investigate the effect of different concentration of sucrose solution on potato chips.

Hypothesis:

I would expect the potato chips to turn flaccid when they are placed in a strong sucrose solution because the water from within the cells will diffuse out leaving the potato flaccid. The potato chips left in the weak sucrose solutions should turn turgid in a weak sucrose solution, due to the water being absorbed by osmosis into the cells of the potatoes, this will make the potato chip larger in size. I should also be able to find some potato chips, which have neither increased nor decreased in size because the concentration in the potato is the same as the sucrose solution, so no mass or length would be gained or lost.

Scientific knowledge:

Osmosis is a type of diffusion, where the molecules move from an area of high concentration to an area of low concentration passing through a partially permeable membrane. When distilled water or a weak sucrose solution or a diluted sucrose solution is used, the water molecules will pass through the semi-permeable membrane into the potato. This is due to the fact that the water is more concentrated outside, so the molecules in the water will move through the permeable membrane, and in this experiment it will pass through into the potato.  The potato chip will increase in length, and weight due to osmosis. When a strong sucrose solution or a concentrated sucrose solution is used, the water within the potato will move out of the potato through the semi-permeable membrane, and into the strong sugar solution, of which the potato is soaked in. This will cause the potato chip to shrink in length and mass.

Key Variable:

Independent variable/s: concentration

Dependant variable/s: mass, length, volume of solution

Controlled variable/s: temperature, size of chip, time  

Concentration is an independent variable because we can control and change the concentration to our desired concentration.

Mass, length and volume are dependant variables because our whole experiment depends on these variables, which we can alter and change to a desired amount.

The temperature and time are controlled variables because they should be kept the same for each potato chip and solution through-out the experiment because temperature is a catalyst and may speed up osmosis if the best temperature is reached, and if the temperature is too hot it may damage the cells in the potato chips.  

Risk assessment: 

Preliminary Experiment

Join now!

Aim:

To have a practice run of the actual experiment and make alterations and improvements to the method designed, so that when the final experiment is held, there would be less criticisms and more reliable results.

Apparatus list:

  • Beakers (3)
  • Digital balance
  • Forceps
  • Petri-dish
  • Measuring cylinder
  • Stop clock
  • Scalpel
  • Ruler
  • White tile
  • Potato chipper
  • Potato (1-2)
  • Paper towels
  • Coloured pins
  • Sticky labels
  • China graph pencil

Method:

  • Prepare the potatoes for the potato chipper by cutting the edges of the potatoes off with a scalpel, on a white tile.
...

This is a preview of the whole essay

Here's what a teacher thought of this essay

Avatar

*** Overall a well planned and carried out experiment which needed more thought put into the discussion of results and the evaluation of the method. Planning was well carried out with a trial experiment. The prediction could be made clearer. If the prediction could be made quantitative ( perhaps by doing some background research) this would be helpful Obtaining results The student carried out and trial experiments and a good range of the independent variable with a fair number of repeats. The student should try to ensure all units and concentrations are clearly recorded. It would have been better to only use one method of recording the dependent variable. This would have allowed more time for repeating anomalous results. Analysing Evidence and Evaluation The graph was not available to view. The student needed to explain the extent to which the conclusion supported the prediction and look at ways of improving the reliability of the evidence. The student should try to account for the anomalies mentioned.