A student investigates the reaction between calcium carbonate (marble chips) and excess dilute nitric acid. In each experiment, she uses the same mass of marble chips and measures the mass of carbon dioxide gas released. She records the time taken for the reaction to completely stop.
Look at her results:
| Experiment | Size of marble chips | Reaction time (s) | Mean rate of gas loss (g/s) |
|---|---|---|---|
| 1 | large | 500 | 1.20×10−31.20 \times 10^{-3}1.20×10−3 |
| 2 | large | 220 | |
| 3 | large | 120 | 5.00×10−35.00 \times 10^{-3}5.00×10−3 |
| 4 | small | 60 | 1.00×10−21.00 \times 10^{-2}1.00×10−2 |
Look at the student's results for experiment 2.
Calculate the mean rate of gas loss in experiment 2.
Give your answer to 3 significant figures and in standard form.
31 exam-style questions on OCR GCSE Chemistry Controlling reactions. Each one has a worked solution and a mark scheme showing where the marks go.