Potato Osmosis Lab Report

Find out the concentration of the cell contents of a potato

Introduction

Osmosis is the diffusion of water from a lower concentration of solute to a higher concentration of solute through a partially permeable membrane. This lets smaller molecules such as water, pass through but does not allow bigger molecules through. The molecules continue to diffuse until they reach a balanced state, where no area has a higher or lower concentration than any other.

In a high concentration of water the amount of sugar solution is low.

This is called a weak/dilute solution. In a weak concentration of water the amount of sugar solution is high. This is called a strong/concentrated solution.

When a semi-permeable membrane divides two solutions,

To conduct a fair test I will ensure that the experiment is carried out at room temperature. The size of the potato is an important factor, as the amount of weight lost or gained will alter. Also the potato cylinders will be weighed before and after the experiment to see if osmosis has taken place. The type of potato I will use will stay the same as different potatoes may absorb at different rates.

Planned Method

A range of sugar solutions will be arranged with concentrations……………..

Sections of potato will be cut with a scalpel and measured with a ruler. This has to be done carefully as the difference of surface area may allow more or less osmosis to occur. The mass of each cylinder will be weighed to ensure consistency. I will do each experiment three times so that I can take an average for each sugar solution. By doing this I will receive more accurate results and therefore draw up a more accurate conclusion. I will also use 20 ml of each solution and

Evaluation

In my opinion the experiment went well. I gathered a sufficient quantity of results that allowed me to create an informative graph.

The time used for the experiment was a good choice as it gave enough time for osmosis to occur. The amount of concentrations was about right, but if I were to repeat the experiment I would maybe use higher ranges. In my opinion the cutting of the potatoes was the hardest part as although I was only recording the mass for my results, it could have affected the surface area and therefore the general rate of osmosis.

Through my findings I did not find any anomalies. The only possible incorrect things could have been that on removing the potatoes from the beakers, one could have been more dried more thoroughly than the others and so would have had excess water, this would add to the mass.

If the experiment was repeated I would find another way to dry off the potatoes that would ensure they were dried the same way for the same amount of time.

To extend this experiment I could by looking at the potato cylinders through a microscope, this would enable me to see the cells in greater detail and draw some more observational