Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Changing the pressure on the reaction
19 practice questions
Practice questions
11–19 of 19
Question 11
3 marks · Normal
Answer and see the solution →A reaction between two gases at 100 kPa takes 10 minutes to complete. If the pressure is increased to 200 kPa, assume the rate doubles. Calculate the new time for the reaction to complete.
Show your working.
Question 12
3 marks · Normal
Answer and see the solution →Explain, using particle theory, why changing the pressure has little effect on the rate of reactions involving only liquids.
Question 13
4 marks · Normal
Answer and see the solution →The table below shows the time taken for a reaction between two gases at different pressures.
Reaction time at different pressures Pressure (kPa) Time to complete reaction (s) 50 40 100 20 200 10 (a)[1 mark]Describe how the time taken changes as the pressure increases.
(b)[2 marks]Calculate how many times faster the reaction is at 200 kPa compared to 50 kPa.
(c)[1 mark]Explain why the reaction is faster at higher pressures.
Question 14
1 mark · Normal
Answer and check →Which statement best explains why increasing the pressure of a reaction involving only liquids has little effect on the rate?
- A.Liquid particles are already close together, so increasing pressure does not significantly increase the number of collisions.
- B.Increasing pressure causes liquids to evaporate quickly.
- C.Higher pressure breaks down liquid molecules.
- D.Liquids expand a lot when pressure changes.
Question 15
2 marks · Normal
Answer and see the solution →Describe the effect of increasing the pressure on a reaction between two gases, and link your answer to particle collisions.
Question 16
4 marks · Normal
Answer and see the solution →(a)[1 mark]State whether changing the pressure has a significant effect on the rate of reaction for solids or liquids.
(b)[2 marks]Describe the arrangement of particles in solids and in liquids.
(c)[1 mark]Explain, using your answer to (b), why pressure does not change the rate much for solids and liquids.
Question 17
2 marks · Hard
Answer and see the solution →A chemical reaction between nitrogen and hydrogen gases is taking place in a sealed vessel. The pressure inside the vessel is increased while the temperature remains constant.
Describe and explain what happens to the rate of reaction when the pressure is increased.
Question 18
5 marks · Hard
Answer and see the solution →A student investigates the effect of pressure on two reactions:
(a)[3 marks]Reaction 1: Two solid powders are mixed together in a sealed container. Predict what happens to the rate of reaction if the pressure is increased. Explain your answer using particle theory.
(b)[2 marks]Reaction 2: Two liquids are mixed together. Explain, using your knowledge of particle arrangement, why increasing the pressure has little effect on the rate of reaction.
Question 19
2 marks · Hard
Answer and see the solution →A reaction takes place between two gases. The pressure is increased by decreasing the volume of the container.
Explain why this leads to a faster reaction rate, using ideas about particle collisions.