insoluble – a substance that does not dissolve in a solvent
solvation – the process of surrounding solute particles with solvent particles to form a solution
When a solid solute is placed in a solvent, the solvent particles completely surround the surface of the solid solute.
If attractive forces between the solute particles and the solvent are greater than the attractive forces holding the the solute particles together, the solvent particles pull the solute particles apart and surround them.
+ - - - NaCl Na = Cl = H 2 O H = O = + - + Process of Solvation - + + - + + + - - + + - + - - + - + - + - + - + + - + + - + + - + + - + +
Water- Universal Solvent
Dipoles allow solvation of ions and polar molecules
Factors that Affect the Rate of Solvation
Agitate the solution (stirring)
increase the temperature of solvent
increase the surface area of the solute
SOLUBILITY – refers to the maximum amount of solute that will dissolve in a given amount of solvent (at a specified temperature and pressure)
saturated – a solution that contains the maximum amount of dissolved solute (for a given temp & pressure than a saturated solution)
unsaturated – a solution that contains less dissolved solute (for a given temp & pressure than a saturated solution)
Units of Solubility
g of solute
100 g water
read these units as:
“ grams of solute per 100 grams of water ”
Here are some for you to try.
What mass of solute will dissolve in 100mL of water at the following temperatures. Also determine which of the three substances is most soluble in water at 15°C.
NaCl at 100°C
NH4Cl at 90°C
supersaturated – a solution that contains more dissolved solute than a saturated solution at the same temperature