Diffusion: past paper questions
Real questions on diffusion
The newest 20 of 37 written questions. Open one to see it on the real paper.
- 0620/32 · May/June 2026 · Q5d[1]
Name the process in which gas particles spread out from an area of high concentration to an area of low concentration.
See it on the paper → - 0620/42 · October/November 2025 · Q1c(i)[1]
Describe, in terms of particles, why gases diffuse. (i)
See it on the paper → - 0620/42 · October/November 2025 · Q1c(ii)[1]
State what determines the relative rate of diffusion of gases at constant temperature.
See it on the paper → - 0620/41 · October/November 2024 · Q1e[1]
is caused by gas particles colliding with each other.
See it on the paper → - 0620/22 · May/June 2024 · Q1[1]
Which gas has the slowest rate of diffusion?
See it on the paper → - 0620/42 · February/March 2024 · Q5a[1]
Suggest why but-1-ene diffuses quicker than butane.
See it on the paper → - 0620/32 · May/June 2023 · Q8c(iii)[3]
Sulfur dioxide gas turns aqueous acidified potassium manganate( VII ) from purple to colourless. Fig. 8.2 shows a gas jar of sulfur dioxide separated from a gas jar of air by a glass plate. A piece of filter paper soaked in aqueous acidified potassium manganate( VII ) is glued to the top of the gas jar of air. air fi...
See it on the paper → - 0620/42 · February/March 2023 · Q1e(i)[1]
Choose from the list of formulae the gas which diffuses most quickly. Draw a circle around your answer. CH 4 NO 2 SO 2 CO CO 2
See it on the paper → - 0620/22 · October/November 2022 · Q1[1]
The rate of diffusion of three gases, ammonia, carbon dioxide and methane, is measured. What is the order of the rate of diffusion of the gases from slowest to fastest?
See it on the paper → - 0620/32 · October/November 2022 · Q4c[3]
Concentrated aqueous hydrobromic acid releases fumes of acidic hydrogen bromide gas. A long glass tube is set up as shown. cotton wool soaked in concentrated hydrobromic acid damp blue litmus paper At first the blue litmus paper does not turn red. After a short time the blue litmus paper turns red. Explain these o...
See it on the paper → - 0620/33 · October/November 2022 · Q4c[3]
Sodium hydroxide is used to make the red dye alizarin. Alizarin is soluble in ethanol. A crystal of alizarin is placed in a beaker of ethanol. After a few hours, the red colour has spread throughout the beaker. ethanol crystal of alizarin at the start after a few hours Explain these observations using the kinetic...
See it on the paper → - 0620/21 · May/June 2022 · Q1[1]
Which two gases will diffuse at the same rate, at the same temperature?
See it on the paper → - 0620/22 · May/June 2022 · Q1[1]
Which two gases will diffuse at the same rate, at the same temperature?
See it on the paper → - 0620/42 · February/March 2022 · Q1e[1]
is the gas with the slowest rate of diffusion at room temperature ����������������������������������������������������������������������������������������������������������������������������������������������
See it on the paper → - 0620/22 · October/November 2021 · Q1[1]
Ammonia gas diffuses faster than hydrogen chloride gas because its molecules have a lower molecular mass.
See it on the paper → - 0620/33 · May/June 2021 · Q2d(ii)[3]
Concentrated aqueous ammonia releases fumes of ammonia gas. A long glass tube is set up as shown. long glass tube cotton wool soaked in concentrated aqueous ammonia damp red litmus paper t first, the red litmus paper does not turn blue. A After a short time, the litmus paper turns blue. Explain these observations...
See it on the paper → - 0620/42 · February/March 2021 · Q2c(i)[1]
Describe why these gases diffuse.
See it on the paper → - 0620/42 · February/March 2021 · Q2c(ii)[2]
State which of these four gases has the highest rate of diffusion. Explain your answer. gas explanation
See it on the paper → - 0620/11 · October/November 2020 · Q1[1]
‘The movement of a substance very slowly from an area of high concentration to an area of low concentration.’ Which process is being described? A a liquid being frozen B a solid melting C a substance diffusing through a liquid D a substance diffusing through the air
See it on the paper → - 0620/12 · October/November 2020 · Q1[1]
‘The movement of a substance very slowly from an area of high concentration to an area of low concentration.’ Which process is being described? A a liquid being frozen B a solid melting C a substance diffusing through a liquid D a substance diffusing through the air
See it on the paper →
What examiners said
Better performing candidates were able to relate the higher rate of diffusion of but-1-ene to its lower Mr. Weaker responses simply referred to but-1-ene being ‘lighter’ or ‘less dense’ or having a ‘lower Ar’. Several candidates gave incorrect reasons such as ‘but-1-ene has 2 fewer H atoms’ or ‘but-1-ene has a double bond’.
— Examiner report, February/March 2024, 0620/42 Q5(a) (Cambridge)
The ‘kinetic particle theory’ question was the last question on this paper. The main mistakes were not being specific and talking about ‘molecules’ or ‘particles’. Some candidates wrote down that ‘molecules spread from a low concentration to a high concentration’, which was incorrect.
— Examiner report, May/June 2023, 0620/32 Q8(c)(iii) (Cambridge)
Most candidates opted for CH4 as the gas which diffuses quickest. Many thought it was CO, presumably because it has the fewest atoms in a molecule.
— Examiner report, February/March 2023, 0620/42 Q1(e)(i) (Cambridge)
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