A student placed potato cylinders in sucrose solutions of different concentrations for 30 minutes.
The Table shows the results.
Table
| Concentration of sucrose solution in mol/dm3\text{mol/dm}^3mol/dm3 | Starting mass in g\text{g}g | Final mass in g\text{g}g | Percentage change in mass |
|---|---|---|---|
| 0.0 | 2.50 | 2.90 | +16.0 |
| 0.2 | 2.40 | 2.58 | +7.5 |
| 0.4 | 2.60 | 2.55 | X |
| 0.6 | 2.50 | 2.20 | -12.0 |
| 0.8 | 2.40 | 1.98 | -17.5 |
Calculate the percentage change in mass, X, for the cylinder in the 0.4 mol/dm3 sucrose solution.
Give your answer to one decimal place.
Explain why the cylinder in the 0.0 mol/dm3 sucrose solution gained mass.
Explain why the student calculated the percentage change in mass, rather than just the change in mass.
Give the concentration of sucrose solution in the Table that is closest to the concentration of the solution inside the potato cells.
Give a reason for your answer.
41 exam-style questions on Edexcel GCSE Biology 1.4 Transport across cell membranes, covering 1.4.1 Transport into and out of cells and 1.4.2 Percentage gain and loss in osmosis. Each one has a worked solution and a mark scheme showing where the marks go.