Wednesday, September 4, 2019
How does the concentration of sucrose affect the weight Essay -- GCSE
How does the concentration of sucrose affect the weight of pieces of potato after osmosis has taken place? Aim The aim of this is experiment is to investigate how much sucrose is in a potato. We are going to investigate the effect of different concentrations of sucrose on the weights of pieces of potato after osmosis has taken place. Prediction I predict that the less concentrated the solution of sucrose is, the greater the weight of the potato will be. I predict this because osmosis is the movement of water from a region of high water concentration to a region of low water concentration through a semi-permeable membrane i.e. the cell wall of the potato. If the concentration of water inside the potato is high then the water will pass out through the cell wall, decreasing the weight of the potato. If the concentration of water outside of the potato is high then the water from outside of the potato will pass through the cell wall into the potato, thus increasing the weight of the potato. A low concentration of sucrose will have a greater ratio of water to sucrose, so more water will pass thorough into the potato in an attempt to even up the amounts of water and sucrose on both sides. If the concentration of sucrose outside of the potato is high then there will be less water to pass through into the potato and the potato will therefore lose water from inside in an attempt to even up the concentrations of sucrose and water on both sides. If the cell has lost water then it will not weigh as much as a cell full of water as the cell will be flaccid. If the cell has gained water then it will be turgid and will weigh more. The higher the concentration of the sugar solution, the faster osmosis will take place. I think this because the more sugar in the water, the longer it will take for it to balance out. Some background information Osmosis is the movement of water from an area of high concentration (lots of water particles) to an area of low concentration (few water particles). It is only the movement of water, as only water particles are small enough to pass through the semi-permeable cell membrane of the plant. Osmosis makes plants cells swell up if they are surrounded by a weak solution i.e. a lot of water, and they therefore become turgid. This is useful in giving support for cells and opening stomatal guard cel... ...in that will affect the next measurement. Our results were also left by a window, so the temperature could have been affected if the window was open or the weather outside was hot. To improve this experiment next time we can also make sure that we leave the test tubes in the test tube racks nowhere near anything that will affect the temperature i.e. a heater or a window. The conclusion may only be valid only within a certain range, if we were to use even more precise concentrations of sucrose solution then we can eventually find out the precise concentration that provides the correct answer. The concentrations used were slightly too vague as I had to say that the answer must lie between two amounts. However, if we were to improve the experiment by narrowing down the concentrations we will use even more then this will be time-consuming and very tedious. Therefore, it will not be a good idea to try and improve the experiment in this way. To extend this investigation we can also experiment changing the following variables: ÃÅ¾ Temperature of the experiment ÃÅ¾ Surface area of the pieces of potato ÃÅ¾ Weight of the potato ÃÅ¾ How long the experiment is left for.