Biology Osmosis

Biology Osmosis

  • Submitted By: sonofa
  • Date Submitted: 04/14/2013 12:14 PM
  • Category: Science
  • Words: 1616
  • Page: 7
  • Views: 125

Chosen Method

For my chosen method I will be measuring the mass to investigate how different sodium chloride solutions affect osmosis.
Independent variable: 20ml Sodium chloride concentration (1%, 2%, 3%, 4%, 5%) I am using 5 concentrations as it will give me a wider range of data.
Dependent variable: Mass of potato chips (g) for each concentration of sodium chloride. This will be measured in grams before and after it is put in the solutions. I will be measuring in grams because my results would be precise and would give a closer deviation to the exact values.

Controlled variables:
* Temperature of solution should be controlled as osmosis works faster in higher temperature. I will keep the temperature the same at all times (being that the temperature should be at room temperature).
* Surface area of the potato chip before added to the concentration. This will need to be controlled as the different sizes may have different concentrations and will be an unfair test. To ensure this I will use the same size potato borer as the borers are of different sizes. I will also use relatively same size potatoes.
* Concentration of sodium chloride, which is the dependent variable in this experiment. This will be altered in order to complete the experiment and making sure that the concentrations are the exact values.
* Timing for experiment, if longer then I should expect to see a different length size. To make it fair this should keep constant; 15 minutes should be timed consistently for every experiment.
One whole potato – I will be using only one potato because using the same potato will keep my test controlled as different potatoes may have different concentrations. I will need 5 potato chips using a potato borer.
Potato borer – I will need the same size borer so that the surface areas of the potato chips are the same.
Scalpel –I will need to cut of any peelings left on the potato chips as the peelings can effect the movement of...

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