osmosis I have chosen to test what effect the concentration of sucrose solution has on the chips.
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Biology Coursework - Osmosis Introduction For my Biology coursework I am investigating osmosis. I am doing a practical to find out how osmosis affects one of the variables listed below. Variables * Temperature * Concentration of sucrose solution * Time in solution * Beginning mass of chip * Amount of distilled water with the sucrose solution * Beginning surface area of chip Idea I have chosen to test what effect the concentration of sucrose solution has on the chips. Prediction * I think that the chips in the test tubes containing more sucrose solution than distilled water will increase in temperature. * I think that the chips in the test tubes containing less sucrose solution than distilled water will decrease in mass. * I think that the chips in the test tubes containing equal amount of sucrose solution and distilled water will stay roughly the same mass. I think the graph of the results will turn out like the sketch I have drawn below. Page 1 Reason Osmosis is the passage of water molecules from a region of high water concentration, through a semi-permeable membrane to a region of low water concentration.
3.48 3.63 3.7 From the results that I got from my pre-experiment I have decided to measure my official tests over a 1 hour period. This is because that was where the biggest change occurs. At 24 hours the changes start to decrease. I have come across the problem that I cannot measure for one hour because I need 10 minutes at the beginning of each lesson to get my equipment set up. Due to this I am going to measure the changes in mass of the chips over 50 minutes. I will do this three times to get good, accurate results. Page 3 Method * Collect up all the equipment and set up five test tubes. * Then fill the first test tube up with 20ml of sucrose solution. Fill the second test tube up with 15ml of sucrose solution and 5ml of Distilled water. Fill the third test tube with 10ml of each sucrose solution and distilled water. Fill the forth test tube with 5ml of sucrose solution and 15ml of distilled water.
I am going to repeat my experiment three times to get accurate results. Page 4 Equipment list * 20 test tubes (concluding the three repeats) * 20 2cm long potato chips * Sucrose solution * Distilled water * Accurate scales * Stop watch * Razor blade * Measuring cylinder * Paper towel Safety To make my experiment safer I made sure I handles each test tube carefully so I did not smash them. Before I started my experiment I made sure my bags were well out of the way so that I did not trip over them while carrying out my experiment. I made sure I washed my hands thoroughly after I had finished my experiment. I made sure I did not rush when putting away my apparatus because this is how accidents can be caused. I did not carry out my experiment until I knew there was a teacher present in the lab. I made sure I followed the laboratory regulations while conducting my experiment. Page 5 ?? ?? ?? ?? GCSE Biology Coursework - Osmosis Jamie Hannath 11JWT
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