What is the difference between osmosis and diffusion?

Osmosis is the movement of water across a semi-permeable membrane, while diffusion is the movement of particles from high to low concentration.

Osmosis and diffusion are both passive transport processes, which means they do not require energy and occur naturally. However, they differ in the types of particles they transport and the conditions required for the process to occur.

Osmosis specifically refers to the movement of water molecules. It occurs when there is a concentration gradient across a semi-permeable membrane, which allows water but not solute particles to pass through. Water molecules move from an area of lower solute concentration (higher water concentration) to an area of higher solute concentration (lower water concentration) to achieve equilibrium. This process is crucial in biological systems, for example, in the regulation of water content in cells.

On the other hand, diffusion is a more general process that involves the movement of any particles, including atoms, ions, and molecules, from an area of higher concentration to an area of lower concentration. This movement continues until the concentration of particles is equal in all areas, achieving equilibrium. Diffusion can occur in any mixture, including gases, liquids, and even within solids, and does not require a semi-permeable membrane.

In summary, while both osmosis and diffusion are passive transport processes aiming to achieve equilibrium, osmosis is specific to the movement of water across a semi-permeable membrane, and diffusion refers to the movement of any particles from an area of high concentration to an area of low concentration. Understanding these processes is fundamental to the study of chemistry and biology, as they underpin many essential biological and chemical phenomena.