Investigating Osmosis in Plants

Aim

The aim of our experiment is to measure osmosis in plants. We have chosen to investigate the concentrations of sugar solutions to see which is the best for osmosis to occur in. The sugar solutions range from 0 molar (water) 2 molar 4 molar 6 molar 8 molar 1.0 molar 2.0 molar (syrup).

Equipment

The equipment we are going to use is as follows: -

• Glass Beakers – we are using clear glass beakers to place the three chips of potato in and the different sugar concentrations. Were also using clear glass beakers so that we could see what was it going happen inside the beaker and to see weather osmosis is taking place.
• Measuring Cylinders – we are using measuring cylinders to measure exactly how much of the sugar concentrated solution is needed to make it a fair test. This means osmosis should take place evenly in turn with the other beakers.
• Potato Corer – we are using potato corers to measure identical chips of potato so it’s a fair test. Otherwise osmosis could happen faster or slower in one of the potato chips compared to the others.
• Knife - we are using a knife to cut the potato chips to make them the right size as all the others therefore making it a fair test.
• Pen – we are using a board marker to write down on the beakers which sugar concentrations are which so we don’t get mixed up when recording our results.
• Ruler – we are using a ruler to measure the size of the potato chips before and after the experiment has taken place. This is to see how much if any the potato chips have increased or decreased in size due to osmosis.
• Measuring Scales – we are using measuring scales to measure the weight of the potato chip before and after the experiment has taken place. This is to see how much if any the potato chips have increased or decreased in size due to osmosis.

 

Prediction

I predict that osmosis will occur the most in the chips that have been placed in the sugar solution labelled 0 molar (water) this is because the potato will find it easier to soak up the water compared to the syrup like solution labelled 2.0 molar. I predict there will be a steady decrease in osmosis as the sugar concentrations increase.

Method  

To complete the experiment we needed a potato, with the potato with drilled out twenty-one chips using a potato corer. Then we cut them down the right size with a knife making sure all the skin of the potato was taken off to make it a fair test. Then we weighed each chip to make sure they were the same weight and measured them with a ruler to make sure they were the same size. Then we measured out different sugar concentrated solutions in a measuring cylinder and poured them into seven different glass beakers labelled 0.0m all the way through to 2.0m. Then we placed three potato chips in each beaker of different solutions and waited to collect the results to see which beaker osmosis had taken place in the most and the least and to see whether osmosis had even happened at all. We put three chips into each beaker instead of one so that we could take the average of the three to make sure that it wasn’t a freak result and to make it a fair test.

Fair Test

I have made the experiment a fair test in many ways these are using a glass beaker this means you can see the experiment more clearly. By using a measuring cylinder, ruler, measuring scales and a knife. These made it a fair test because it made sure all the measurements are equal and the same. Another way of making it a fair test was to place three potato chips in the different solutions instead of one. This is because if one of the readings from the potato chip is unusual then there is another two chips to take the reading from.

Sources

For information on my investigation and osmosis I looked through some science books and Microsoft Encarta 2000. I found the following picture on osmosis.