Ksp oct 2013.notebook
October 30, 2013
Solubility Product Equilibrium Constant (Ksp)
Objective: Describe the relationship between the solubility product constant and the solubility of a compound. Oct 29­2:25 PM
Solubility Product Equilibrium Constant (Ksp)
Example: AgCl(s) <­­> Ag+(aq) + Cl­(aq)
Ksp= [Ag+][Cl­]
= 1.8 x 10­10
This solubility equilibrium only applies to saturated solutions that are in contact with excess undissolved solid in a closed system. The SMALLER the value of Ksp, the LOWER the solubility of the compound. Nov 2­2:31 PM
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Ksp oct 2013.notebook
October 30, 2013
Write the dissociation equation, the solubiity product constant expression and the value of ksp (page 562) for each of the following:
a) calcium fluoride: CaF2(s) <­> Ca2+(aq) + 2F­(aq) Ksp= [Ca2+][F­]2= 3.9 x 10­11
b) Silver chromate:
Ag2CrO4(s) <­­>2Ag+(aq) + CrO42­(aq) Ksp= [Ag+(aq)]2[CrO42­(aq)]=1.2x10­12
c) aluminum hydroxide Al(OH)3
Al(OH)3(s) <­> Al3+(aq) +3OH­(aq)
­34
Ksp= [Al3+(aq)][OH­(aq)]3= 3.0 x 10
d) calcium carbonate
2­
CaCO3(s) <­> Ca2+(aq) + CO3 (aq) ­9
2­
2+
Ksp=[Ca (aq)][CO3 (aq)]=4.5 x10
List the compounds from most to least soluble:
calcium carbonate, calcium fluoride, Silver chromate, aluminum hydroxide. Nov 2­2:42 PM
Define:
Solubility­ The amount of a substance that dissolves in a given quantity of a solvent at specified conditions of temperature and pressure to produce a saturated solution. Solubility constant­ an equilibrium constant applied to the solubility of electrolytes; it is equal to the product of the concentrations of the ions each raised to a power equal to the coefficient of the ion in the dissociation equation. Nov 2­2:54 PM
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Ksp oct 2013.notebook
October 30, 2013
Sample Problem 18.3
What is the concentration of lead ions and chromate ions in a saturated lead chromate solution at 25 degrees C? (Ksp= 1.8X 10­14)
Nov 5­8:41 PM
Lead (II) sulfide (PbS) has a Ksp of 3.0 x 10­28. What is the concentration of lead (II) ions in a saturated solution of PbS?
2.0 X 10­14M
Nov 5­8:47 PM
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Ksp oct 2013.notebook
October 30, 2013
What is the concentration of Calcium ions in a saturated calcium carbonate solution at 25 degrees ? Ksp =4.5 x 10­9
6.7 x10 ­5
Nov 5­8:49 PM
Calculate the concentration of strontium and fluorine ions in strontium fluoride solution at room temperature given that Ksp is 2.46 x 10­9
Oct 29­2:45 PM
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Ksp oct 2013.notebook
October 30, 2013
Write a explanation of the common ion effect. Nov 5­8:51 PM
Finding Ksp in the presence of a common ion
Photographic film is covered with a light sensitive emulsion containing silver bromide. The Ksp of silver bromide is 5.0 x 10­13. What is the bromide­ion concentration of a 1.0 L saturated solution of AgBr to which 0.020 mol of AgNO3 is added?
Nov 5­9:01 PM
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Ksp oct 2013.notebook
October 30, 2013
Nov 6­2:24 PM
Nov 6­2:27 PM
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