1. Molecular diffusion in liquids  Diffusion of solutes in liquids is very important in many industrial processes, especially in liquid-liquid extraction or solvent extraction, gas absorption,and distillation.  Diffusion in liquids also occurs in many situations in nature, such as oxygenation of rivers and lakes by the air and diffusion of salts in blood.

2.  the rate of molecular diffusion in liquids is considerably slower than in gases.  the flux in a gas is not that much greater, being only about 100 times faster,  the resistance to diffusion in a liquid are much greater than in gas