A student investigated osmosis using equal-sized cylinders of parsnip root tissue.
The student placed the cylinders in six different concentrations of sodium chloride solution, including distilled water. The cylinders were left for the same time at the same temperature.
The table shows the results.
| Concentration of sodium chloride solution in mol/dm³ | Percentage change in mass |
|---|---|
| 0.00 | +13.2 |
| 0.05 | +8.4 |
| 0.10 | not calculated |
| 0.15 | −1.6 |
| 0.20 | −5.2 |
| 0.25 | −9.6 |
The table shows the measurements for the cylinder placed in the 0.10 mol/dm³ solution.
| Initial mass in g | Final mass in g |
|---|---|
| 2.50 | 2.59 |
Calculate the percentage change in mass for the cylinder placed in the 0.10 mol/dm³ solution.
Use:
percentage change in mass = change in mass ÷ initial mass × 100
Describe the effect of increasing the concentration of sodium chloride solution on the percentage change in mass.
The concentration of the cell contents is between two of the concentrations tested.
Give these two concentrations.
Explain why the cylinder placed in distilled water increased in mass.
140 exam-style questions on AQA GCSE Biology 1.3 Transport in cells, covering 1.3.1 Diffusion, 1.3.2 Osmosis, and 1.3.3 Active transport. Each one has a worked solution and a mark scheme showing where the marks go.