Diffusion
Science: KS3, topic 2.1.8
Diffusion
Diffusion is the net movement of particles from an area of high concentration to an area of lower concentration. It describes the movement of particles in fluids (liquids and gases). The particles all move randomly.
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Diffusion of a soluble solid in water
- Add purple potassium permanganate solid to water.
- The purple potassium permanganate solid starts to dissolve. -
- The purple colour begins to diffuse until the colour (concentration) is evenly spread out.
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Diffusion of a coloured gas
- Place bromine gas in a gas jar with a separator.
- Remove the separator. The bromine gas will begin to diffuse into the lower gas jar until the colour (concentration) is evenly spread out.
Test yourself on Diffusion
What do we call the movement of particles from a higher concentration to a lower concentration?
Select the correct statement in each pair
Why does the purple colour from dissolved potassium permanganate spread until it is evenly spread through the water?
Potassium permanganate dissolving in water and bromine gas spreading between jars are both examples of diffusion. Which one happens in a liquid?