A student investigates the rate of reaction between solid calcium carbonate (CaCO3\text{CaCO}_3CaCO3) and dilute hydrochloric acid (HCl\text{HCl}HCl) to produce calcium chloride, carbon dioxide, and water.
The reaction is carried out under two different sets of conditions, Trial 1 and Trial 2, as shown in the table below:
| Condition | Trial 1 | Trial 2 |
|---|---|---|
| Temperature (∘C^\circ\text{C}∘C) | 60 | 20 |
| State of CaCO3\text{CaCO}_3CaCO3 | Large lumps | Fine powder |
Explain, in terms of collision theory, why it is not possible to predict whether the rate of Trial 2 will be faster or slower than the rate of Trial 1.
Practise Edexcel GCSE Chemistry Rates of reaction with exam-style questions for Foundation and Higher tier. 166 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
