I'm confused with diffusion and its properties and osmosis and its properties. Please solve my doubt.
The constituent particles in solids are very closely packed. Hence diffusion occurs rarely in solids as particles in two solids cannot intermix with each other. Solids can diffuse into liquids and gases comparatively easier than into solids. There are examples in which solid can diffuse into solid such as formation of alloys.
The rate of diffusion of liquids is higher than that of solids. This is due to the fact that in the liquid state, particles move freely and have greater space between each other as compared to particles in the solid state.
However, the rate of diffusion is maximum in gases, as spaces between the constituent particles of gases are larger as compared to both liquids and solids.
If two solutions of different concentration are separated by a semi-permeable membrane which is permeable to the smaller solvent molecules but not to the larger solute molecules, then the solvent will tend to diffuse across the membrane from the less concentrated to the more concentrated solution. This process is called osmosis.
Osmosis is of great importance in biological processes where the solvent is water. The transport of water and other molecules across biological membranes is essential to many processes in living organisms. The energy which drives the process is usually discussed in terms of osmotic pressure.