An Investigation Into The Factors Affecting Osmosis

... rp knife, which could injure someone if it's not handled properly. I will also be very careful that the solutions don't get into our bodies internally, just in case, because we are not fully aware of the damage it could do to us. I will also be wearing an apron due to any solutions getting to my clothes.

But other than that, there weren't any bigger matters to be cautious of.

Method:

I plan to carry out this experiment by using all the safety issues and fair testing procedures to give me the most reliable and most accurate set of results.

I plan to have a range of sugar solutions prepared with concentrations from 0.1M to 1.0M, in intervals of 0.1, (but I will only be taking 6 of these 10 molarities, as this should be more than enough to explain the effects of the potato on osmosis). Then sections of potato will be cut using a cork borer and knife to equal lengths (5cm) keeping the surface area constant. I will then measure each tissue of potato using a measuring scale, measured in grams, when I do this I will place the boat on the scale and resetting the scale so that I only get the weight of the potato and not with the boat. I will then add 20ml of each concentration of sugar in two test tubes, giving me a total of 12 test tubes, and labelling each molar reading. Then to each test tube a cut piece of potato will be added and its concentration added to the label. These will be left for 1 hour. Then the potato pieces will be removed from the test tubes, and surface solution on the potato will be removed using paper towels. I will then measure the potatoes again, recording its change in mass by weighing them. I will then be taking the two readings of each molar concentration. This is because I will be doing a repetition of the experiment, as it will save me valuable time. These results will be taken for each concentration in order to get an average and reduce the effect of anomalous resulting.

As it is difficult to get the cut potato pieces to the same mass it was decided that I will use a percentage change in mass which will be used to compare the data in the results, as this would be far more accurate. I will do this by taking the difference in mass, divide it by the mass before of he potato and multiplying it by 100.

After looking at my preliminary work it suggested that there wasn't enough concentrations of sugar to compare each result to each other, so their will be 8 different sugar concentrations to choose from for the actual experiment. The timing of the potatoes weren't left for enough time in the preliminary experiment, as the results didn't have much change ...