Factors Affecting the Rate of Dissolution

Dissolution is  a process whereby solute is attracted to the solvent forming a solution.  Dissolution can either proceed faster or slower depending on the different situations.   What do you think are the factors affecting the rate of dissolution?

Temperature

Temperature affects the rate of dissolution most especially for solid in liquid solutions.  Try dissolving 1 tablespoon of sugar in two different glasses.  One glass containing hot water and the other glass with cold water.  Which glass will dissolve sugar faster?  Of course glass containing hot water.    But why?  The molecules in hot water have more kinetic energy than in cold water, therefore the interaction between solute and solvent is more faster than in the cold one and so the faster is the rate of dissolution.  Therefore, dissolution increases at a higher temperature, and decreases at lower temperature.


Particle Size or Surface Area

Does the size of the particles affects the rate of dissolution?  Which will dissolve more faster in a glass of water,  1 tablespoon of  finely fine iodized salt or the rock salt? Why?  The answer is the iodized salt because of it smaller particles size therefore, it has large exposed surface area that can immediately allow the molecules to interact faster with the solvent.  This means that the smaller the particle size or the larger the surface area the faster is the rate of dissolution.


Rate of Stirring

Stirring does also affect the dissolution process.  Stirring more rapidly the mixture, the faster is the rate of dissolution and the slow you stir the mixture, the slower is the rate of dissolution.   Why?  Stirring more rapidly the mixture also allows the interaction of solute and solvent faster.