What this practice covers
These questions are drawn from past CIE 0620 Chemistry papers and filtered to diffusion. You answer, you find out immediately whether you were right, and you get the reasoning for the correct option and for each distractor. Wrong answers go to a mistakes locker so you can come back to exactly those.
Practice is free. You need an account only so your progress and your mistakes are still there next time.
Start practising practice questions →
What examiners see students get wrong here
These are the errors that cost marks on diffusion, taken from our own topic notes. Read them before you practise and you will recognise the traps in the questions.
- Saying particles move from high to low concentration because they "want more space". They move at random.
- Saying diffusion occurs in solids.
- Saying the white ring forms in the middle of the tube, or nearer the ammonia end.
- Saying the heavier gas diffuses faster because it has more energy. At a given temperature the energies are equal, so the heavier particle is the slower one.
- Explaining the bromine jar by saying bromine is denser and sinks, when the whole design of the experiment is that the bromine moves upwards.
- Stirring or warming the water in the potassium manganate(VII) experiment, which replaces diffusion with convection.
Revise it first
If any of the above is unfamiliar, work through the notes before practising: Diffusion revision notes.