OSMOSIS EXPERIMENT - STUDENT REPORT

Summary version

Detailed version

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OSMOSIS EXPERIMENT REPORT - SUMMARY VERSION:
STAGE 1	We prepared an 80% sucrose solution, and placed exactly 20mls in a Vising tubing "cell" We measured the exact length of the column of sucrose in the cell: in this case 14cm We immersed the cell in exactly 300mls distilled water for 20 min
STAGE 2	We took repeat measurements - The column of liquid inside the Visking tubing cell had increased to over 20cm The level of liquid in the cylinder outside the cell had dropped to 270mls
Control: we set up a similar experimental cell, containing only water - no loss or gain of volume was observed Conclusion: We presumed that the water that left the cylinder moved by osmosis into the very concentrated sucrose solution inside the Visking cell, accounting for the rise in volume therein. top

OSMOSIS EXPERIMENT REPORT - DETAILED VERSION:
1	We cut 40cm lengths of Visking tubing		top
2	We soaked it in water to soften it		top
3	We used 80g sucrose as our solute		top
4	We dissolved this in 100mls water		top
5	This gives us 80% sucrose, a very concentrated solution		top
6	We used 20mls of the sucrose solution		top
7	We tied a knot in one end of the softened Vsking tubing		top
8	This gives us a sealed pocket		top
9	We carefully poured the 20mls sucrose into the Visking tubing		top
10	We tied off the other end to form a sealed "cell"		top
11	We measured the length of the column of liquid inside the tube - 14cm, and lowered it into 300mls pure water		top
12	We repeated for Experiment B, putting pure water inside the tubing and immersing in 300mls sucrose; Control C has pure water inside and outside the tubing		top
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14	Tube A had increased in length from 14cm to 20cm and had become very turgid, while the water level in the cylinder dropped from 300mls to 270mls		top
15	Tube B had decreased in length from 14cm to 8cm and become very flaccid, while the water level in the cylinder has risen to 320mls		top
16	The levels in Contol C stayed the same throughout		top
Conclusion We repeated the experiment again and the results were the same The water is diffusing from where it is more plentiful to where it is mre scarce i.e. moving from the weaker solution to the stronger solution every time. if there is no difference in solution the water does not move. This is happening without any input of energy. This diffusion of water is called OSMOSIS			top