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Osmosis coursework. The aim of this investigation is to find the best concentration of salt solution to preserve chips in, so there is no net movement of water in or out of the chip.

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Introduction

Osmosis coursework Scenario: Mr Chips runs a busy chip shop. He cuts his chips early in the morning and stores them in water which allows him to quickly fry and serve his chips when it gets too busy at lunch time. Mr Chips asked his son to help him in the chip shop one day. His son John asked his dad why he stored the chips in water before frying them. Mr Chips said "The water stopped them from browning" John informed his dad that by putting potatoes into water caused them to absorb water. The more water they absorbed the more oil they would take up when they were fried, making them unhealthy. John told his dad that the potato chips should be stored in salty water so they did not take in or release any water. Aim: The aim of this investigation is to find the best concentration of salt solution to preserve chips in, so there is no net movement of water in or out of the chip. Scientific theory Diffusion is when particles spread in random motions from places with high concentration to places with low concentration. The particles move in a random motion because they collide frequently. The particles will keep mixing until they are evenly distributed. The concept of diffusion is driven by concentration gradient but diffusion still happens when there is no concentration gradient. The diagram below shows this. Osmosis is a special type of diffusion involving only water molecules. It is physical process of when water molecules move across a semi permeable membrane (a membrane which allows certain molecules to pass through it by diffusion) ...read more.

Middle

as the prediction that I said for my preliminary which is that: My prediction is that the low concentration solution (0 - 0.4) salt solutions will make the chips turgid because the solution will be hypotonic on the other hand the chips in the concentrated solution (0.6 - 1.0) will make the chips lack in firmness. So I think the 0.5 salt solution would be the best concentration to store the chips in because the solution will not make the chips absorb water nor loose much water because the solution would be isotonic which makes this the perfect concentration to store the chips in. Variables: Independent variable: The concentration of salt solution Dependant variables: There are two dependent variables, these are the length and mass of the chips Controlled variables: Control variable Why does it need to be controlled How you are going to control this Consequence of not controlling it Amount of solution To make it a fair test By measuring carefully An unfair test Amount of excess water To make sure the test is accurate Compressing the chips An inaccurate test Size of potato chips So all chips are equal Cut the chips at an equal length The chips wont all absorb the same amount which will lead to a unfair test Shape of chips mass If one chip is bigger than the others it will absorb more than the others which will lead to inaccurate results By weighing the chips and making sure there are the same weight It will corrupt the results Apparatus Quantity Reason why this is being used Accuracy and reliability Small beakers 11 To put the different salt solutions in Same beaker size Stopwatch 1 To time how long the chips have been in ...read more.

Conclusion

I could easily make a firm conclusion with the range of salt solutions I used. If I needed to measure solutions with similar measurements as these salt solutions I would definitely use the range of salt solutions that I have used for this experiment. d) Have you collected enough data which is accurate and reliable to support a firm conclusion? Yes I have collected enough data for my conclusion to rely on. e) Did you have any problems with your method? I only had one problem that was on my first solution I put slightly more salt solution than I was supposed to by accident. f) Did you choose the most suitable equipment for your task? Yes I chose the best equipment possible for my investigation. g) Did you control the other variables in your investigation? Do you think they varied during the experiment? Yes I controlled all of the other variables in my investigation and most of them varied. h) How precise are your results? E.g. did you read off values or measure them using an instrument? Were the divisions on the equipment that you used small enough to record adequate readings? My results were roughly precise however I feel that I could have made them even more accurate if I had done the experiment more slowly and carefully. i) What level of accuracy can you get from the equipment used? I got a high level of accuracy from the equipment I used. j) What improvements can be made to obtain more accurate and reliable results? To cut the chips more slowly and carefully. k) What extra measurements could be taken to make your conclusion more secure? The investigation would have been better if the volume was measured. ?? ?? ?? ?? Steven bangar 10 blue ...read more.

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