Diffusion

Diffusion

Diffusion happens when particles spread from higher to lower concentration. It requires a concentration gradient).

Potassium Manganate (VII) Experiment

Diffusion through liquids is very slow if the liquid is totally still. This can be shown but dropping a piece of potassium manganate (VII) into water. It can take days for the colour to spread because the gap between each particle is small.

The Bromine Experiment

Showing diffusion in gases can be done by filling a lower gas jar with bromine gas and topping it with a gas jar filled with air. The bromine particles and air particles will eventually bounce around to give an even mixture.

The Ammonium Chloride Experiment 

This experiment is used to show that particles in different gases travel at different speeds. It relies on the reaction between ammonia and hydrogen chloride gases to give white solid ammonium chloride.

A white ring of ammonium chloride would form near the hydrochloric acid. This shows that ammonia particles have travelled further to reach the hydrogen chloride gas, showing that it travels faster.