Solubility

1
Solubility

• Def. the maximum amount of solute that will
  dissolve in a given amount of solvent AT a
  specified temperature and pressure. (expressed in
  g solute/100 g solvent)
• Example g sugar/100 g water
• What happens to the excess solute if you add more
  than the maximum?
• Table 15-2, p457

2
Solubility, continued.

• Solubility at the particle level
• As more solute particles are added to the
  solvent, there are fewer solvent particles to
  surround the added solute particles.
• As the solute particles move around, some will
  bump into the undissolved particles and will be
  attracted back to join the solid crystal solute
  particles.

3
Solubility, continued.

• Define
• Saturated solution
• Supersaturated solution
• Factors that affect solubility
• Pressure --- only affects solubility of gaseous
  solutes and gaseous solutions
• Temperature --- HOW???

4
Solubility, continued.

• Supersaturated solutions (solns) are formed when
  a solution is saturated at a higher temperature,
  and then cooled.
• http//www.youtube.com/watch?vXSGvy2FPfCwsafety_
  modetruepersist_safety_mode1
• Real-world use Rock candy ?

5
Solubility, continued.

• The solubility of a gas in any solvent increases
  as its external pressure (the pressure above the
  solution) increases. (Think carbonated sodas!)
• Henrys Law At a given temperature, the
  solubility (S) of a gas in a liquid is directly
  proportional to the pressure (P) of the gas above
  the liquid.
• How would you write Henrys Law in an equation?

6
Assignment

• Practice Problems p.461 (1-2)
• Section Assessment p.461 (7)