CHEMISTRY GCSE PAPER 2 QUESTIONS AND CORRECT ANSWERS

CHEMISTRY GCSE PAPER 2 QUESTIONS AND CORRECT ANSWERS Equation for rate of reaction - Answer-Rate of reaction = Amount of reactant used or amount of product formed / Time What is activation energy? - Answer-energy needed for a successful collision to occur When do chemical reactions occur? - Answer-when reacting particles collide with each other with sufficient energy How does temperature affect the rate of reaction? - Answer-Increased temperature means increased energy within the system Particles move quicker Particles have more energy Increased likelihood of colliding and increased likelihood of colliding with sufficient energy More successful collisions How does concentration affect the rate of reaction? - Answer-At higher concentrations there's a higher number of particles in a given volume Giving a higher likelihood of collision Increasing the number of successful collisions How does surface area affect the rate of reaction? - Answer-More particles are exposed and therefore available for colleens so there's a higher number of colleens and a higher number of successful collisions REQUIRED PRATICIAL: Investigate how changes in concentration affects the rate of reaction - Answer-1. Place a flask on a piece of paper with a cross drawn on it 2. Add sodium thiosulfate to the flask 3. Add hydrochloric acid and start stopwatch 4. Stir the reactants with a glass rod 5. Watch the cross through the flask 6. Once the cross is no longer visible stop the stopwatch 7. Repeat experiment with different concentrations of hydrochloric acid