Constants
- Size of beaker
- Volume of deionised water within tubing
- Volume of NaCl solution (20%)
- Materials and apparatus
- Time of submersion
Materials
- 500mL Deionised water
- 2L 20% NaCl solution
- 10 Dialysis Tubes
- 10 beakers (250mL)
- 10 petri dishes
- 10 stirring rods
- Sticky labels
- 2 measuring cylinders (200mL)
- Volumetric pipettes (50mL)
- 2 teat pipettes
- Cotton string
- Scissors
- Timer
- Electronic balance
- Paper towels
Method
1. The beakers and measuring cylinders were rinsed and dried to remove any cause for errors.
2. Sticky notes were used to label each beaker and petri dish with the concentration of NaCl (0%, 5%, 10%, 15%, 20%).
3. The concentration of each solution was made by measuring particular amounts NaCl and deionised water in separate measuring cylinders. For precision, all the solutes were measured at eye level, from the bottom of the meniscus.
- The 0% solution contained 200mL of deionised water
- The 5% solution contained 50mL of NaCl solution and 150mL of deionised water
- The 10% solution contained 100mL of NaCl solution and 100mL of deionised water
- The 15% solution contained 150mL of NaCl solution and 50mL of deionised water
- The 20% solution contained 200mL of NaCl solution
The solutions were then stirred with separate stirring rods to mix the NaCl solution and the deionised water into a homogeneous solution.
4. The dialysis tubes were carefully split to create an opening using a small, sharp pair of scissors. The tubes were then completely opened carefully through the middle to the other end using the scissors. The ends of each tube were twisted and tied in a double knot with the cotton string to prevent any leakage. Any part of the tube past the knotted end that was over 2cms ...
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... NaCl solutions and opening the dialysis tubes. Apparatus needed to be manipulated skillfully to attain more precise results for comparisons and observations. The apparatus also needed to be handled with care to prevent any breakages, especially because a lot of equipment was made of glass. Skills were required when understanding the ratios to determine the range of concentrations and creating the various NaCl solutions. This was a critical skill because the concentration of NaCl in the solution was the independent variable and a fault would have greatly influenced the results. Splitting, opening and tying the dialysis tubes needed to be completed with care and competence because it was an imperative part of adequately representing the cell. Any mistake or inconsistency in this process would have negatively affected the results when observing the process of osmosis.
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* In the first dialysis tube (bag A), we would insert ten mL of one
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Step 5: Pour the water and salt into a seperate container so you have serperated the sand and salt.
when to do it etc. This should lead me to good results at the end of
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