Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Diffusion in gases
19 practice questions
Practice questions
1–10 of 19
Question 1
1 mark · Easy
Answer and see the solution →What is the name given to the process by which the particles of a liquid or gas spread out and mix without stirring?
Question 2
3 marks · Easy
Answer and see the solution →A student places a jar of coloured gas below a jar containing only air and quickly removes the lid between them.
(a)[1 mark]State what will eventually be seen in both jars.
(b)[2 marks]Explain why it takes some time for the colour to spread through both jars, using ideas about particles.
Question 3
2 marks · Easy
Answer and see the solution →At room temperature, particles in a gas travel at about 500 m/s. The laboratory is 6 m long.
Calculate:
(a)[1 mark]How long it would take a particle, travelling in a straight line at this speed, to reach the other end of the laboratory.
(b)[1 mark]Explain why, in reality, it takes much longer for a smell to spread across the laboratory.
Question 4
2 marks · Easy
Answer and see the solution →Explain, using the particle model, why diffusion happens faster in a gas than in a liquid.
Question 5
3 marks · Easy
Answer and see the solution →The table shows how long different gases took to diffuse through air in a set apparatus during an experiment.
Time taken for diffusion of different gases through air. Gas Time to mix fully (seconds) Hydrogen 40 Oxygen 60 Ammonia 35 Carbon dioxide 70 (a)[1 mark]Which gas diffused the fastest?
(b)[1 mark]Which gas diffused the slowest?
(c)[1 mark]Suggest, using particle ideas, why there is a difference in the speed at which these gases diffuse.
Question 6
1 mark · Easy
Answer and see the solution →What do you call the uneven spread of particles before diffusion is complete?
Question 7
3 marks · Easy
Answer and see the solution →Two gases, X and Y, are released at opposite ends of a glass tube. After a short time, a white ring forms closer to the end where gas Y was released.
(a)[1 mark]Which gas, X or Y, diffused faster?
(b)[2 marks]Explain why the white ring appears closer to the Y end.
Question 8
2 marks · Easy
Answer and see the solution →A small bottle of perfume breaks at one end of a corridor 18 metres long. If perfume particles travel randomly at an average speed of 600 m/s, calculate:
(a)[1 mark]The time it would take a perfume particle to reach the other end in a straight line, in seconds.
(b)[1 mark]Explain why the actual time to smell the perfume at the other end is much longer.
Question 9
2 marks · Normal
Answer and see the solution →Explain what is meant by diffusion in gases, using the idea of particles.
Question 10
4 marks · Normal
Answer and see the solution →(a)[1 mark]Figure 1 shows an apparatus used to investigate the diffusion of bromine gas.
Apparatus for diffusion of bromine gas State what you would observe if the lid between the two gas jars is removed.
(b)[2 marks]Explain why the observation described in (a) happens, using ideas about particles.
(c)[1 mark]Suggest why the bromine gas eventually spreads throughout both jars.