Osmosis coursework

To make this a fair test I will keep the potato chips the same weight and size because it could affect the rate of osmosis. I will also keep the amount of distilled water I use the same. My potato chips will be 2.37g each and will be left to there solutions for twenty-four hours.

I think the that the potato chip left in distilled water will gain weight and will become turgid as the concentration of water in the potato chip will be lower than the concentration of the distilled water. I think that the sucrose you add to the distilled water the lower the mass of the potato chip after osmosis has occurred will be. This is because the solution of sucrose and distilled water will gave a lower concentration than the water inside the potato chip so the potato chip will become flaccid. There will be a point during the experiment where the concentration of molecules is equal (isotonic).

I will use the weighing scales to accurately measure the weight of the potato chips and I will make sure they are the same weight. The measuring cylinder can be used to measure the liquids in ml.

METHOD

First I cut out six potato chips and cut off any skin that was on them. Then I weighed them and made sure they were all the same weight. After that was done I measured out the solutions of distilled water and sucrose and poured them in to test tubes. I then labelled the test tubes and placed a potato chip in each one. Twenty-four hours later I collected my results.

EVIDENCE

I was able to use the apparatus in a safe manner and caused no injuries to me or anyone else.

My results are:

* Distilled water - potato chip 2.97g

* Distilled water + 0.1 sucrose - potato chip 2.8g

* Distilled water + 0.2 sucrose - potato chip 2.11g

* Distilled water + 0.3 sucrose - potato chip 2.03g

* Distilled water + 0.4 sucrose - potato chip 1.64g

* Distilled water + 0.5 sucrose - potato chip 1.48g

Potato chips before osmosis occurred were 2.37g

Potato chips after osmosis had occurred:

Solution

Dis. Water

0.1 suc.

0.2 suc.

0.3 suc.

0.4 suc.

0.5 suc.

Weight of chip

2.97g

2.8g

2.11g

2.03g

.64g

.48g

My results range from 1.48g to 2.97g.

The average of my results is 2.171666666 or 2.27(to 2d.p).

CONCLUSION

I found that my results show that the more sucrose you add to the distilled water the more the weight of the potato chip decreases from it's original weight.

The pattern I can see in my graph shows that the more sucrose you add to the distilled water the less the potato chip weighs after osmosis has occurred.

A SCATTER GRAPH OF MY OSMOSIS RESULTS

EVALUATION

I think my experiment was successful. My results were accurate and I used a suitable method. To improve my results I would repeat the test and use a potato chipper to make the chips the exact same weight, size and shape. My results are reliable as the potato chips were all roughly the same weight and were all the same size and shape. To make my results more reliable I could have made sure the temperature of the solutions were the same and the light intensity on the experiments was kept the same at all times.