A lump of calcium carbonate and the same mass of powdered calcium carbonate are added to separate flasks of excess dilute acid. Why does the powder react faster?
It has a larger surface area, so collisions are more frequent
It has a larger surface area, so collisions are more energetic
It has a larger total volume, so more acid particles can react
It has a lower activation energy, so more collisions succeed
41 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.