Pichayut Viwatrujirapong (Earl) IB Biology SL IB Self-Design lab Diffusion of Water in Gummy BearIntroduction: Diffusion is the movement of particles from the area of high concentration to the area of lowconcentration until the concentration reaches the equilibrium point where the concentrations in bothareas are equal. In addition to that the diffusion of water is called Osmosis, which is the movement ofwater across the selectively-permeable membrane, where the water moves from higher water potentialor low solute to lower water potential or high solute. For example, if the water potential outside thecell (20% Salts solution outside) is lower than the water potential inside the cell (5% inside) ,therefore the water will diffuse out of the cell and cause the cell to shrivel. Diffusion is very important to cells because it is use to transport material in and out of thecells such as nutrients and waste and if there is not diffusion the cell will not be able to get rid ofwaste material and get nutrients in therefore the cells will die. For example, if there is higherconcentration of Carbon Dioxide inside the cell more than outside the cell and the cell wanted to getrid of Carbon Dioxide in its cell therefore the cell uses diffusion to transport Carbon Dioxide out ofthe cell by moving it down the concentration gradient. In this investigation, the rate of diffusion in Gummy Bear (symbolize as cells and the Gummybear skin symbolize the cell membrane therefore the material will diffuse in and out of Gummy bear)in the different temperatures will be investigated. The Gummy bear will be place in three differentcontainers which will be fill with saturated salt solution in three different temperatures condition, onein warm temperature, one room in temperature , and one in cold temperature. As a result of this, theeffect of the temperature on the rate of diffusion will be reveal.Hypothesis: The Gummy Bear in the highest temperature saturated salt solution will shirk the most,because the salt solution will diffuse out of the Gummy Bear quickest. On the other side, the GummyBear in the lowest temperature salt solution will shrink least because the salt solution will diffuse outof the Gummy Bear slowest, and the Gummy Bear in the room temperature will shrink a little bit.
Design:Research Question: What is the effect of the temperature on the rate of diffusion in the Gummy Bear?What is the effect of temperature on the rate of diffusion in a Gummy Bear?Variables: The dependent variable is the rate of diffusion in the Gummy Bear and the independentvariable is the temperature of the saturated salt solution. In addition to that there are severalcontrolled variables that were kept constant throughout the investigation are the length of theGummy Bear, the concentration of the saturated salt solution , color of the gummy bear, and thetemperature of the solution. The temperature of the solution was kept constant to make sure thediffusion rate of the certain temperature was constant. The size, color, and the length are kept samein order to keep the rate of diffusion constant too. The temperature (measure by usingthermometer) in lower temperature condition is controlled by the temperature of the freezeradjustment in the refrigerator, and the water in the higher temperature condition is controlled bythe water bath, and the temperature in the room temperature condition is controlled by putting it inthe cupboard which it will not be affected by the air condition but it is hard to keep the temperatureconstant therefore this made it as the weakness of the experimental design. In addition to that thesame color, same amount of concentration of the saturated salt solution (by mixing it in the sameamount of concentration 10% = 900 ml of water with 90 grams of salt and pour 300 ml if saturatedsalt solution in three 500 ml beakers) and choose the closet length and size Gummy Bear (bymeasuring it by using ruler and electronic balance) were used for all trails also to keep constant.Material:3 – 500 ml beakers12- Gummy Bears: 4 for each color – red, white, yellow, and green900 ml - water90 grams - salt1 - Ruler1 - Electronic Balance1 - Water Bath1 – Refrigerator3 – Thermometers15 – Ice cubes
Procedure: 1) Measure the length and weight of gummy bear using ruler and electronic balance 2) Fill up 3 500ml beakers with 300 ml of 10% salt saturated solution in to each beakers 3) Heat up one beaker by putting it in the water bath, put ice in one beaker and put it in refrigerator, and left the last beaker in the room temperature condition which is in the cupboard and measure these beaker temperature. The water bath, refrigerator, and cupboard help to keep the temperature constant. 4) Measure the temperature of the three saturated salt solution until the temperature reaches 55 °C, 25 °C and 3 °C. 5) Put in 4 gummy bears into each beaker – red , white , yellow, and green 6) Left it for 3 hours and 50 minutes. 7) Measure and record the volume and the length of the gummy bear 8) Calculate uncertainties and the increase or decrease of size of the gummy bear. 9) If have time repeat this experiment one more time to improve the precision.Data Collection and processing:Data TableTable 1: Beaker 1 (higher temperature solution) - Original size and length and Color of the GummyBear before putting into the salt solution Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green 2.24 20 Yellow 2.34 20 Red 2.35 19.8 White 2.35 20Table 2: Beaker 2 (room temperature solution) - Original size and length and Color of the GummyBear before putting into the salt solution Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green 2.32 18 Yellow 2.30 19 Red 2.34 18 White 2.32 19
Table 3: Beaker 3 (lower temperature solution) - Original size and length and Color of the GummyBear before putting into the salt solution Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green 2.33 20 Yellow 2.34 19 Red 2.32 20 White 2.33 19Table 4: Beaker 1 (higher temperature solution) –size and length and Color of the Gummy Bear afterput in the saturated salt solution for 3 hours and 50 minutes Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green - (dissolved) - (dissolved) Yellow - (dissolved) - (dissolved) Red - (dissolved) - (dissolved) White - (dissolved) - (dissolved)Table 5: Beaker 2 (room temperature solution) –size and length and Color of the Gummy Bear afterput in the saturated salt solution for 3 hours and 50 minutes Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green 2.12 17.5 Yellow 1.98 18 Red 2.14 17.5 White 2.16 18.5Table 6: Beaker 3 (lowest temperature solution) –size and length and Color of the Gummy Bear afterput in the saturated salt solution for 3 hours and 50 minutes Color of the Gummy Bear Mass of the Gummy Bear Length of the Gummy Bear (±0.01 grams) (±0.1 mm) Green 2.23 20 Yellow 2.21 19 Red 2.19 20 White 2.17 19
Table 6: Average of size and length and Color of the Gummy Bear before and after put in thesaturated salt solution for 3 hours and 50 minutes Beaker Average Mean of Average Mean of Average Mean Average Mean Mass of the Gummy Length of the of Mass of the of Length of the Bear before put in Gummy Bear Gummy Bear Gummy Bear the solution before put in the after put in the after put in the (grams) solution solution solution (mm) (grams) (mm) Beaker 1 (Hotter 2.32±.055 19.95±0.1 - (dissolved) - (dissolved) temperature) Beaker 2 (Room 2.32±.04 18.5±0.5 2.1±.09 17.88±0.5 temperature) Beaker 3 (Lower 2.33±0.1 19.5±0.5 2.2±0.3 19.5±0.5 temperature)Table: 7: The average of the decrease of in the mass and the length of the Gummy Bear Beaker Average Mean of Mass of the Average Mean of Length of the Gummy Bear decrease by Gummy Bear decrease by (grams) (mm)Beaker 1 (Hotter temperature) 2.32±.055 19.95±0.1Beaker 2 (Room temperature) 0.22±.13 0.62±.1Beaker 3 (Lower temperature) 0.13±.04 0 (stay the same length)Sample calculation:i) Mean of mass/length of the gummy bear:= (Mass 1 + Mass 2 + Mass 3 +Mass 4) / 4= (2.24-2.34+2.35+2.35) / 4= 2.32 gramsii) Uncertainty of mean mass/length of the gummy bear= Range / 2= (20 – 19.8) / 2= ±0.1 grams
Graphs :Average rage of mass loss in each beakers:
Conclusion and Evaluation:According to these results, the results show that as the temperature increases the faster the diffusion is, because if compared the average of the decrease in mean of mass of the Gummy Bear and theaverage of the decrease in mean of mass of the Gummy Bear the higher temperature is the one thathave the biggest mass and length lost , that its mass decreased by 2.32±.055 grams and its lengthdecreased by 19.95±0.1 mm. In addition to that comparing literature value graph and with theexperimental graph these graph shows the same result which is the higher the temperature the higherthe rate of diffusion.Evaluation One of the big error in the design of the method is that the method of measuring the amountof water and the amount of salt, because in this investigation the measurement of 900 ml of water wasdone by using the 500 ml beaker and it is not accurate way of measuring the amount of watertherefore to improve this we could use a more precise scale which use a measuring cylinder of 100mlinstead of 500 ml beaker and in addition to that when we are measuring the amount of salt we cannotget the exact 90 grams of salt because the measuring scale is only in the hundredth scales and toimprove this precision on the next experiment we could use the thousands scales electric balanceinstead using hundredth scale balance. One of the big problem in the carrying out the experiment are that the time managementproblem that in the investigation the timing was not that good and therefore it made the results seemto be unclear for example the higher temperature beaker because it is still a mystery when did theGummy Bear dissolved in the salt solution substance, but to fix this problem next time in theinvestigation a person should check out the Gummy Bear every 10 minutes and it would make theresult more precise and clearer too. Not only that the data is not that accurate too because in thisinvestigation there is no result of the higher temperature beaker gummy bear of the higher temperaturebeaker because the Gummy Bears dissolved in the saturated salt solution. The significance of each ofthe weaknesses on the results is that it made the results seem to be unclear and not precise andaccurate. Lastly if there is more time to do this investigation doing more trails would definitelyimprove this investigation results for sure.