A student compares the rate of reaction between marble chips (calcium carbonate) and hydrochloric acid of different concentrations. The reaction is significantly faster when using 2.0 mol/dm3 hydrochloric acid compared to 0.5 mol/dm3 hydrochloric acid.
Explain, in terms of particles, why increasing the concentration increases the rate of reaction.
127 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.