A student investigates the rate of osmosis in potato tissue by measuring the increase in length of potato cylinders after being immersed in a 0.1 M sucrose solution for 24 hours.
The student repeats the experiment five times under identical conditions and records the increase in length.
The table shows their results:
| Trial | Increase in length (mm) |
|---|---|
| Trial 1 | 12.5 |
| Trial 2 | 12.9 |
| Trial 3 | 18.9 |
| Trial 4 | 12.2 |
| Trial 5 | 12.7 |
Identify the anomalous trial.
Calculate the mean increase in length of the potato cylinders. You must not include the anomalous result in your calculation. Give your answer to 3 significant figures.
8 exam-style questions on OCR GCSE Chemistry Practical skills. Each one has a worked solution and a mark scheme showing where the marks go.