Key Concept: Increasing temperature, concentration, surface area or adding a catalyst increases the rate of reaction.
Section A: Experiments
1. Describe how you would investigate the effect of surface area using marble chips and acid. [3]
2. Explain the effect of increasing concentration on the rate of reaction. [2]
Section B: Data Interpretation
3. 25 cm3 of acid reacts in 80 s at 20 C and 40 s at 30 C. Calculate the change in rate (factor). [2]
4. Name one catalyst used in decomposition of hydrogen peroxide and its effect. [2]
Total marks: 9
Mark Scheme
1. Compare powdered vs large chips with same mass and acid volume; measure CO2 volume or time for reaction [3]
2. More particles per volume; more frequent collisions; faster rate [2]
3. Rate doubled; factor of 2 (time halves) [2]
4. MnO2 or KI; increases rate without being used up [2]