A student investigates the rate of reaction between marble chips (calcium carbonate) and dilute hydrochloric acid. The reaction is carried out in an open conical flask placed on a digital balance. The student records the total mass of the flask and its contents every 30 seconds.
| Time / s | 0 | 30 | 60 | 90 | 120 | 150 | 180 | 210 | 240 |
|---|---|---|---|---|---|---|---|---|---|
| Mass of flask and contents / g | 150.00 | 148.80 | 147.95 | 147.40 | 147.10 | 147.00 | 147.00 | 147.00 | 147.00 |
Explain the trends shown by the data in the table.
230 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.