Biology IA - Investigation of the relationship between surface area and volume using different volume agar cube lab report
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Introduction
Biology HL Candidate name: Ieva Drulyte Date: ___________________ Investigation of the relationship between surface area and volume using different volume cubes of agar being put into sodium hydroxide solution D, DCP, CE Design Aim: to investigate how the distance diffused by solution to agar cubes depends on cubes surface area and volume ratio. Hypothesis: bigger surface area and volume ratio of agar cubes approaches the result of the entire agar cube being diffused. Variables: the distance diffused by NaOH solution into the agar cube (dependent variable) will be measured by manipulating the size of agar cube (independent variable). The controlled variables are as follows: Contolled variable Units Effect Method to keep it constant Time Min Would alter the rate of diffusion Accurate chronometer will be used Temperature �C Experiment will take place at the same classroom Amount of NaOH mL Agar cubes will be put in the excess of NaOH Concentration of NaOH % The same solution will be used in all trials Concentration of agar cubes % The same agar will be used during all trials Tools: 1. ...read more.
Middle
3x3x3 0.5 0.05 5. 4x4x4 0.5 0.05 ? 0.05 0.05 0.05 The data from the table 1 was processed with the intense to show how surface area and volume ratio changes the ratio of diffused distance and possible distance. Table 2 Processing raw data: surface are and volume ratios, diffused and shortest distances ratios. No. Size of cube (cm) Surface area (cm2) [1] Volume (cm3) [2] [1] and [2] ratio Shortest dist. to cube center (cm) [3] Cm diffused [4] [4] and [3] ratio Percentage (%) 1. 1x1x1 6.0 1.0 6.0 0.5 0.5 1.0 100 2. 1x2x4 28 8.0 3.5 0.5 0.5 1.0 100 3. 2x2x2 24 8.0 3.0 1.0 0.5 0.5 50.0 4. 3x3x3 54 27 2.0 1.5 0.5 0.(3) 33.(3) 5. 4x4x4 96 64 1.5 2.0 0.5 0.25 25.0 ? 0.05 0.0025 0.000125 0.05 0.05 0.05 0.05 0.50 I repeated the experiment 2 times and the date was the same the second time as I used the same tools and the same method. ...read more.
Conclusion
A great improvement in this experiment's method would be to use lots of different forms of agar jellies, for example, ball, star, rhomb, etc. There might be some weaknesses and limitations while performing this experiment. First, the method might be erroneous due to the pH of water used to make agar cubes. Water used to make agar cubes might have been slightly basic or acidic and, therefore, alter the results by making agar cubes more basic or acidic before starting an experiment. Second, parts of cube which are closer to the center do not get colored as much as the pieces which are near the outer walls (because of the pressure and density) and it might be hard to decide where the longest distance travelled by diffusion ends. To make measurements more accurate, only distance travelled by NaOH where pink color can be clearly seen should be counted. However, these weaknesses, possibly, are not very significant, as the results of 2 separate trials were identical. ?? ?? ?? ?? 1 ...read more.
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