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a supplemental resource for students
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The Properties of Mixtures: Solubility
Lecture 18
Saturated solution
contains the maximum amount of dissolved solute at a given
temperature in the presence of undissolved solute.
A saturated solution
In a saturated solution,
processes of dissolving and recrystallizing are in
equilibrium:Solute (undissolved)
Solute (dissolved)
Equilibrium in a saturated solution
Supersaturated solution
contains more than the equilibrium amount of dissolved
solute.It is unstable.
Most solids are more soluble
at higher temperatures.Solute + solvent + heat
saturated solution
Solid solubility vs temperature
Solid solubility vs temperature
Gases are more soluble
at lower temperatures.Solute(g) + water(l)
saturated solution(aq) + heat
Gas solubility vs temperature
Why thermal pollution is bad:Because of increased metabolic rate, living organisms needs more oxygen.Because of lower solubility at the higher temperature, the concentration of oxygen is lower.Because of lower density at the higher temperature, warmer water floats on the cooler and prevent oxygen from reaching it.
Gases are more soluble
at higher pressures.Gas + solvent
saturated solution
The effect of pressure on gas solubility
Henry’s law:
the solubility of a gas (Sgas) is directly proportional to the partial pressure of the gas (Pgas) above the solution:
Sgas = kH x Pgas
kH - Henry’s constant
THE END