Page 112 - Pharmaceutical_Analytical_Chemistry_1_Theoretical_Notes_Level_1

Mansoura National University
Pharm D-Clinical Pharmacy Program Level 1 Pharm. Anal. Chem. 1 (PC 101)

Quiz

1. Calculate the molar solubility of Ag2SO4 in one liter of water. Ksp = 1.4
-5
x 10
-5
2. Calculate the Ksp value of BaSO4 which has a solubility of 3.9 x 10
mole/L at 25°c

Solubility Product Constant (Ksp)

➢ It is the equilibrium constant for the equilibrium between an ionic solid and its
saturated solution.
A B (s) a A (aq) + b B(aq)
a b
a b
Ksp = [A] [B]

Quiz

• Estimate the solubility of Ag2CrO4 in pure water if the solubility
-12
product constant for silver chromate is 1.1 x 10 .
2-
+
Ag2CrO4(s) 2 Ag (aq) + CrO4 (aq)
+ 2
2-
Ksp = [Ag ] [CrO4 ]
• Substitute the equilibrium amounts and the K into the equilibrium
sp
expression and solve for x.
-12 2
1.1 x 10 = [2x] [x]
-5
x = 6.50 x 10 M
-3
-5
• The solubility of barium sulphate at 298 K is 1.05 x 10 mol dm . Calculate
the solubility product.
The equilibrium is:

+2
-2
BaSo4 Ba + So4
Notice that each mole of barium sulphate dissolves to give 1 mole of barium
ions and 1 mole of sulphate ions in solution.

That means that:

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