Factors Affecting Diffusion - Practice Questions & MCQ

• Diffusion can be defined as the movement of particles or ions or molecules of a substance from a region of its higher concentration to the region of its lower concentration.
• The movement of particles or ions or molecules is possible due to their random kinetic energy.
• The particles attempt to distribute themselves evenly or uniformly in the given medium. 
• The process of diffusion follows the second law of thermodynamics, that if no energy enters or leaves the system, then the molecules tend to move from the state of high energy to the state of low energy.

Factors Affecting the Rate of Diffusion:

• The rate and direction of a diffusing substance depends on the concentration of that substance at different locations. 
• It is independent of the other such diffusing substance.
• Temperature: the higher the temperature, the faster the diffusion.
• Surface area: larger the surface area, the faster the diffusion.
• Concentration gradient: higher the gradient, the faster the diffusion.
• Size of particles: smaller particles, faster they diffuse.
• The density of particles: the rate of diffusion is inversely proportional to the square root of the density of the particles. Heavy particles show slow diffusion.
• The medium of diffusion: slowest diffusion in solids, faster diffusion in liquids, fastest diffusion in gases.

Diffusion Pressure: 

• It is the potential ability of a particle or molecule or ion to diffuse from one area of its highest concentration to the other areas of lesser concentration.
• Pure water has the maximum diffusion pressure of 1236 Atm.