The same mass of magnesium reacts with excess acid at 20 ∘C20\,^\circ\mathrm{C}20∘C and at 40 ∘C40\,^\circ\mathrm{C}40∘C. The same final volume of hydrogen is obtained. Why?
Temperature changes the activation energy, not the rate
Both reactions have the same rate, as the same mass is used
Temperature affects the final volume only if a catalyst is used
Temperature affects the rate, not how much magnesium reacts
122 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.