THE SOLUTION PROCESS

Solute and solvent particles are held together by INTERMOLECULAR forces that are important in the formation of solutions.

An EXOTHERMIC (release of energy) process happens if the solvent-solute interaction OVERCOMES the solvent-solvent and solute-solute interaction.

Crystallization of solutes

EXAMPLES

•Condensation of rain from water vapor•Combustion of fuels such as wood, coal•Mixing of alkalis and acids•The setting of cement and concretes

An ENDOTHERMIC (absorption of energy) process happens if the solute-solvent interaction is WEAKER than solvent-solvent and solute-solute interaction.

EXAMPLES

•Cold pack of ammonium nitrate and water•Evaporation of water•Photosynthesis

HYDRATION (SOLVATION) is the process in which an ion or molecule is surrounded by solvent molecules arranged in an orderly manner.

ION –DIPOLEIMF

Crystals that are held by DISPERSION forces (London) dissolves readily in nonpolar solvents.

Classification of solutions based on THE CAPACITY OF THE SOLVENT TO DISSOLVE A SOLUTE.

UNSATURATEDSOLUTION

(less dissolved solute)SATURATED SOLUTION

(max. amount of solute)

Classification of solutions based on THE CAPACITY OF THE SOLVENT TO DISSOLVE A SOLUTE.

SUPERSATURATED SOLUTION(more dissolved solute )

Sodium acetate crystallizing from a supersaturated solution.

SOLUBILITY is the maximum amount of solute that can be dissolved in a given amount of solvent at a certain specified temperature.

There are THREE factors affecting solubility of one substance in another substance.

TEMPERATURE

(higher temp=higher solubility

EXCEPTION: Gases becomes less soluble as

temperature increases.

There are THREE factors affecting solubility of one substance in another substance.

PRESSURE

( no effect on solids and liquids)

(solubility of gases is affected by the pressure change)

There are THREE factors affecting solubility of one substance in another substance.

NATURE OF SOLUTE AND SOLVENT(“like dissolves like”)

Substances with similar types of intermolecular forces dissolve in each

other.

There are several factors affecting the RATE OF THE SOLUTION PROCESS

PARTICLE SIZE OF SOLUTE

& SURFACE AREAThe smaller the particles, the faster the dissolution process

since there is greater exposure of solute on the solvent.

STIRRING and JARRING(shaking)

There are several factors affecting the RATE OF THE SOLUTION PROCESS

INCREASE IN TEMPERATUREMore solute dissolves in HOT solvent than in

COLD solvent.

*the faster the solvents move, the faster it will surround the solute causing the solute to

dissolve.

There are several factors affecting the RATE OF THE SOLUTION PROCESS