Diffusion osmosis planning lab
- 1. Tomoyo Onda IB Biology HL Per. 4 Feb 21. 2010 Mr. Stantus Extreme Temperature Affects to % Change in Mass of Dry Rice Introduction: This experiment aims to analyze the relationship between extreme temperature and the rate of osmosis by absorption (% change in mass). In the daily life, people eat rice almost everyday and it becomes taste good because it absorbs water. According to this, people wander that how much water is absorbed into rice depends on the temperature of pure water. Behavior can be broadly defined as the way organisms respond to their environment. Diffusion is passive movement of particles from a region of higher concentration to a region of lower concentration. Osmosis is diffusion of water across a semipermeable membrane. Some materials are able to easily pass through membranes while others cannot. Water will always move from an area of higher water potential to an area of lower water potential. Rice absorbs water until it reaches its saturation point. For example, cooking rice; people add water into the rice-cooker and in the next couple of minutes the water has be absorbed the rice has increased in volume. The environment condition which may affect the extreme low and high temperature. Rice may rely on the temperature which affect to their rate of osmosis and the weight of itself. This correlation, between temperature and % of osmosis, is what this experiment aims to determine. The purpose of this investigation is to analyze how extreme temperature affects to the % change in mass. This investigation will formulate and test a hypothesis for each experiment. As increase the degree of temperature, the rate of osmosis gets faster and increases the % change of mass because rice absorbs more water when rice is boiled according to a daily cooking. Variables: Independent variable: extreme temperature (0℃, 25℃, 50℃, 75℃, 100℃) Dependent variable: % change in mass of rice Controlled variables: temperature of a room, amount of pure water (200ml), size of a beaker, time of experiment (20 min), type of rice, amount of rice, condition of rice (dried),
- 2. Materials: -5 beakers -Dried rice -Pure water -Cling film -Stop watch -thermometer -incubator -weight measure -ice -camera Procedure: 1. Prepare 5 beakers and put same amount of pure water for each. 2. Put same amount of dried rice into each beaker containing different temperature of pure water. (0℃,25,50,75,100) 3. Covers with a cling film for each beaker to avoid evaporation. 4. Put the beakers into the incubator. 5. Wait for 20 minutes. (Use a stop watch) 6. Measure the weigh of each % change in mass of rice to determine how extreme temperature affects to the rate of osmosis and the weight of dried rice. 7. Record the % change in mass 8. Make a graph for each temperature.
- 3. Data Collection and Processing: Table 1: Change of Mass of Dried Rice in Different Extreme Temperatures Temperature(℃) Change of Mass (g) 1st trial Change of Mass (g) 2nd trial Change of Mass (g) 3rd trial 0 31.06 31.09 30.99 25 31.40 31.63 31.41 50 31.98 31.99 32.00 75 34.37 34.35 34.33 100 71.71 72.01 71.75 Table 1: shows that three trials of how much the mass of dry rice change according to each different temperature after 20 minutes. Table 2: % Change of Mass of Dried Rice in Different Extreme Temperatures Temperature (℃) Change of Mass (%) 1st trial Change of Mass (%) 2nd trial Change of Mass (%) 3rd trial 0 1.24 1.24 1.24 25 1.26 1.27 1.26 50 1.28 1.28 1.28 75 1.37 1.37 1.37 100 2.87 2.88 2.87 Table 2: shows that three trials of how much mass of dry rice changed in % according to each different temperature after 20 minutes. Sample Calculation: Mean (average) (1.24% + 1.24% + 1.24%) / 3 = 1.24% (1.26% + 1.27% + 1.26%) / 3 = 1.263% (1.28% + 1.28% + 1.28%) / 3 = 1.28% Change of % Mass 31.06 g / 25 g = 1.24 % 31.4g / 25 g = 1.26% 31.98g / 25g = 1.28%
- 4. Graph 1: % Change of Mass of Dry Rice in Different Extreme Temperatures Graph 1: shows that how many % changed in mass from 25g after 20 minutes in each different extreme temperature of pure water. especially, the % change of mass of dry rice increased at 75℃ to 100℃.
- 5. Graph 2: Error of % Change of Mass (Error Bar) Graph 2: shows the error which is extending above and below the mean value to show the range of the data. Conclusion: This investigation was to analyze the relationship between extreme temperature and the rate of osmosis by absorption (% change in mass). Table 1 shows that how much grams of dry rice changed from these of 25g after 20 minutes in different temperatures such as 0℃, 25℃,50℃,75℃ and 100℃. According to this table 1, table 2 shows how many % of mass of dry rice changed after 20 minutes in 5 different temperatures of pure water. As a result, dry rice in 0 to 50 ℃ of temperatures does not much change a % change of mass. However, at 75 ℃, they suddenly got a mass a lot such as 1.28 % change of mass to 1.37 %. The graph shows the % change of mass of dry rice and it obviously shows the how much osmosis worked for dry rice. According to this result, as increase the extreme temperature, % change in mass also increases. Especially, at 75 ℃ to 100 ℃, the mass of rice in % increased rapidly. Therefore, the hypothesis was supported.
- 6. Evaluation: When doing this investigation, even though I used incubator, it is hard to make constant temperature while I was counting for 20 minutes. It sometimes decreasing temperature, it is not kind of accurate result. In addition, when the weight was measured, I did not take water completely and carefully so a lot of pure water was also measured when I measure the weight of dry rice after 20 minutes. It was the cause of the fail result that not only the weight of rice after osmosis occurs but also including the weight of water. Therefore, the mass of change of dry rice might change few grams. For the next investigation, it should be careful when making constant temperature by using incubator accurately and the way of measuring should be more careful to find an accurate result.
- 7. Evaluation: When doing this investigation, even though I used incubator, it is hard to make constant temperature while I was counting for 20 minutes. It sometimes decreasing temperature, it is not kind of accurate result. In addition, when the weight was measured, I did not take water completely and carefully so a lot of pure water was also measured when I measure the weight of dry rice after 20 minutes. It was the cause of the fail result that not only the weight of rice after osmosis occurs but also including the weight of water. Therefore, the mass of change of dry rice might change few grams. For the next investigation, it should be careful when making constant temperature by using incubator accurately and the way of measuring should be more careful to find an accurate result.