# Osmosis Lab

Topics: Potato, Concentration, Solution Pages: 4 (730 words) Published: March 15, 2014
Aim:
Investigate the effect of sucrose concentration on osmosis in Solanum tuberosum by recording the change in mass. •Independent Variable: concentration of sucrose (0.0 M, 0.2 M, 0.4 M, 0.6 M, 0.8 M, 1.0 M) (± 0.05) •Dependent Variable: final mass of the cylinders of Solanum tuberosum (± 0.05) •Controlled Variable: temperature, initial length of potato cylinders, volume of the solutions, etc.

Apparatus/Materials:
Solanum tuberosum (potatoes)
Sucrose solution (0.0 M, 0.2 M, 0.4 M, 0.6 M, 0.8 M, 1.0 M) (± 0.05) •Test tubes and rack
Cork borer
Weighing machine (± 0.05)
Weigh boat
Ruler
Scalpel
Method:
1.Use cork borer to cut 5 potato cylinders each with a length of 3 cm. 2.Determine the initial mass of each cylinder.
3.Place a cylinder in 10 cm3 of distilled water (0.0 M solution). 4.Repeat the same steps for each solution.
5.Cover and leave to stand overnight.
6.Remove cylinders and record the final mass of each.
Data:
Qualitative:
When the potato cylinders were taken out of distilled water (0.00 M sucrose solution) they expanded and got stiffer. But when they were removed from 0.2 and 0.4 M sucrose solution, they stayed just about the same. Whereas, when they were extracted from the 0.6, 0.8 and 1.0 M sucrose solutions, they were shriveled and soft. They shrunk in size as well.

Quantitative:
Raw Data:
Recorded (calculated average) data showing the change in masses of cylinders of Solanum tuberosum due to the effect of different concentrations of sucrose solutions. Concentration of sucrose (± 0.05 M)Mass of Solanum tuberosum (mean of 5 trials for each) (± 0.05 g)

InitialFinal
0.00 (distilled water)2.543.18
0.202.482.72
0.402.662.48
0.602.722.68
0.802.521.76
1.002.641.74

Calculations:

Processed Data:
Concentration of sucrose (± 0.05 M)Standard deviation σ (correct to 4 d.p) 0.00 (distilled water)0.0837
0.200.1483
0.400.1013
0.600.3834
0.80...

Cited: Hoong, Tho Lai. "Diffusion and Osmosis." Science 2. Singapore: EPB Pan Pacific, 2007. 76-78. Print.
Kwan, Lam Peng., and Geoff Hayward. "Diffusion, Osmosis and Surface Area : Volume Ratio." Biology: A Course for 'O ' Level. Singapore: Federal Publications, 2004. 23-33. Print.
Ward, William. "Cells; 2.4 Membranes." Pearson Baccalaureate Higher Level Biology. Malaysia: Pearson Education Limited, 2007. 34. Print.