Diffusion Definition in Chemistry

Chemistry Glossary Definition of Diffusion

Diffusion is a natural mass transport mechanism that moves matter from area of high concentration to those of low concentration.
Diffusion is a natural mass transport mechanism that moves matter from area of high concentration to those of low concentration. Science Photo Library Ltd / Getty Images

Diffusion Definition

Diffusion is the movement of a fluid from an area of higher concentration to an area of lower concentration. Diffusion is a result of the kinetic properties of particles of matter. The particles will mix until they are evenly distributed.

Diffusion Examples

  • H2S(g) in a test tube will slowly diffuse into the air of a lab until equilibrium is reached.
  • Food coloring in water diffuses until it's evenly distributed throughout the liquid.
  • Perfume diffuses throughout an entire room.

.
More Diffusion Examples

How Diffusion Works

In diffusion, particles move down a concentration gradient. Diffusion is different from other transport processes in that it results in mixing without bulk matter flow. How it works is that molecules in motion from thermal energy randomly move about. Over time, this "random walk" leads to uniform distribution of different particles.