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Biology · Osmosis · Plant tissue
Osmosis with potato cylinders
Six equal potato cylinders (3.00 g each) are placed in sucrose solutions of different concentration. After 60 minutes they are blotted and re-weighed. The change in mass tells you which way water has moved by osmosis.
t = 0 min / 60 min
Results table
| [sucrose] | m₀ (g) | m₁ (g) | % Δm |
|---|---|---|---|
| 0.0 M | 3.00 | 3.00 | +0.0 |
| 0.2 M | 3.00 | 3.00 | +0.0 |
| 0.4 M | 3.00 | 3.00 | +0.0 |
| 0.6 M | 3.00 | 3.00 | +0.0 |
| 0.8 M | 3.00 | 3.00 | +0.0 |
| 1.0 M | 3.00 | 3.00 | +0.0 |
Exam-style questions
1. At which sucrose concentration was the potato closest to starting mass?
2. What does the crossing point on the graph tell you?
3. Why BLOT the cylinders before reweighing?
4. Why must all cylinders have the SAME starting mass and surface area?