Why does powdered calcium carbonate react faster than equal-mass lumps?
The powder has a higher concentration than the lumps
The powder has more particles than equal-mass lumps
The powder contains a catalyst that lumps do not have
The powder has a larger surface area to volume ratio
54 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.