Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Diffusion in gases
19 practice questions
Practice questions
1–3 of 3 · Hard
Question 1
2 marks · Hard
Answer and see the solution →A laboratory tube is filled at one end with nitrogen gas and at the other end with a coloured gas, chlorine. After some time, the green colour of chlorine spreads along the tube but it takes a few hours until the colour is even throughout.
Explain, using the particle model, why the spreading takes much longer than if chlorine particles could travel in a straight line from one end to the other.
Question 2
5 marks · Hard
Answer and see the solution →A student investigates the rate of diffusion of hydrogen and air using the apparatus shown. In a sealed glass tube, a small amount of hydrogen is released at one end and air at the other. After some time, the gases mix completely.
(a)[2 marks]Describe, using the particle model, how the hydrogen and air particles move inside the tube during diffusion.
(b)[1 mark]Suggest one reason, in terms of particles, why hydrogen diffuses faster than air.
(c)[2 marks]The tube is cooled to a much lower temperature. Predict and explain the effect this will have on the rate of diffusion, using ideas about particle movement.
Question 3
2 marks · Hard
Answer and see the solution →Explain why, when perfume is sprayed in one corner of a large room, the scent is eventually noticed everywhere in the room. Include reference to the movement of gas particles.