Why is diffusion slower in more viscous mediums?

Diffusion is slower in more viscous mediums because the increased resistance hinders the movement of particles.

Diffusion is the process by which particles spread out from an area of high concentration to an area of low concentration. This movement is driven by the kinetic energy of the particles. In a more viscous medium, the particles have to work harder to move around because the medium provides more resistance to their movement.

Viscosity is a measure of a fluid's resistance to flow. It's often thought of as the 'thickness' of a fluid - for example, honey is more viscous than water. The higher the viscosity of a medium, the slower the particles within it will move. This is because the particles have to overcome the greater internal friction of the medium to move from one place to another.

In the context of diffusion, this means that particles will spread out more slowly in a viscous medium. The particles still move from areas of high concentration to areas of low concentration, but they do so at a slower rate because they're hindered by the resistance of the medium.

This concept is crucial in many areas of chemistry, including reaction kinetics. The rate of a chemical reaction often depends on how quickly the reactant particles can move and collide with each other. In a more viscous medium, this movement is slower, which can slow down the reaction rate.

So, in summary, the increased resistance in a more viscous medium hinders the movement of particles, causing diffusion to occur at a slower rate. This has important implications for processes such as chemical reactions, where the rate of reaction can be affected by the viscosity of the medium in which it takes place.