Learning Goals:
Today we will understand the concept of the Solubility
Product (Ksp) (Chapter 7.6 in the text)
Success criteria: We will
a) calculate Ksp (the solubility product constant) (483 –
484)
b) calculate solubility using Ksp values (484 – 486)
c) predict whether a precipitate forms when two
aqueous solutions are mixed using Qsp (the trial ion
product) and comparing it with Ksp) (487 – 490)
d) calculate solubility of solutions with common ions
(common ion effect) (we will use ICE tables to
determine the solubility in solutions) (491 – 492)
Weak solutions:
- tap water contains CO32-, SO42-, Cl-, etc.
- bloodstream
Compounds with low solubilty:
CuCl(s) ↔ Cu+ (aq) + Cl-(aq)
K = 1.7 x 10-7 at 25°C
Equilibrium occurs at the saturation point of the solution.
The K value is called the solubility product constant Ksp.
MgF2 has a solubility of 0.00172 g/100mL
a)
convert this to mol/L
b)
determine Ksp – 2 methods!
What is Ksp if the concentration of zinc carbonate is 3.87
10-6 mol/L?
Given Ksp – calculate solubility
Calculate the solubility of silver iodide at 25°C if the Ksp
is 1.5 x 10-16 at 25°C
Calculate the solubility of zinc hydroxide at 25°C if the
Ksp is 4.5 x 10-17 at 25°C
Predicting Precipitation (Qsp – trial ion product)
If 100 mL of 0.100 mol/L CaCl2(aq) and 100 mL of 0.0400
mol/L Na2SO4(aq) are mixed at 20°C, determne whather a
precipitate will form. For CaSO4(aq) at 20°C, Ksp is 3.6 x
10-6.
If Q > Ksp
Q = Ksp
Q < Ksp
(supersaturated solution) precipitate forms
(saturated solution)
no precipitate forms
(unsaturated solution) no precipitate forms