Post on 16-Mar-2016
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SolubilityLesson 7
Changing solubility
When to and When not to Multiply the Molarity 1. The molar solubility of Ba(OH)2 is 2. Equal volumes of 0.0010 M Ba(NO3)2 and 0.0010 M. Ksp = ? 0.0010 M NaOH are mixed. Will a
precipitate occur?
Ba(OH)2(s) ⇌ Ba2+ + 2OH- Ba(OH)2(s) ⇌ Ba2+ + 2OH-
s s 2s 10.0010 1 0.0010 M 2 2
0.00050 M 0.00050 M
Multiply by 2 because of Ba(OH)2(s) Do not multiply by 2 because of NaOH
Ksp = [Ba2+][OH-]2 TIP = [Ba2+][OH-]2
Ksp = [s][2s]2 TIP = [0.00050][0.00050]2
Ksp = 4s3
Ksp = 4[0.0010]3 TIP = 1.25 x 10-10
Ksp = 4.0 x 10-9 TIP < Ksp No ppt.
3. AgNO3(s) is added to 1.0 L of a solution containing Cl- in order to precipitate out the Cl- as AgCl(s). After the AgCl(s) is filtered out what is the remaining concentration of Cl-?
AgCl(s) ⇌ Ag+ +Cl-
s s s
Ksp = s2
1.8 x 10-10 = s2
s = [Cl-] = 1.3 x 10-5 M
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
The molar solubility is the amount of AgCl(s) in moles per litre that dissolves into ions to form a saturated solution.
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
The molar solubility is the amount of AgCl(s) in moles per litre that dissolves into ions to form a saturated solution. If this equilibrium shifts to the right, the molar solubility increases.
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
The molar solubility is the amount of AgCl(s) in moles per litre that dissolves into ions to form a saturated solution. If this equilibrium shifts to the right, the molar solubility increases. If this equilibrium shifts to the left, the molar solubility decreases.
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
The molar solubility is the amount of AgCl(s) in moles per litre that dissolves into ions to form a saturated solution. If this equilibrium shifts to the right, the molar solubility increases. If this equilibrium shifts to the left, the molar solubility decreases. Like all equilibriums, only changing the temperature changes the Ksp.
Changing the Solubilty of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
The molar solubility is the amount of AgCl(s) in moles per litre that dissolves into ions to form a saturated solution. If this equilibrium shifts to the right, the molar solubility increases. If this equilibrium shifts to the left, the molar solubility decreases. Like all equilibriums, only changing the temperature changes the Ksp. Most solid equilibriums are endothermic.
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3
Increases the [Ag+] and shifts the equilibrium left
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl
Increases the [Cl-] and shifts the equilibrium left
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2SIncreases the [Cl-] and shifts the equilibrium left
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S S2- is low solubility with Ag+ so they react and [Ag+] decreases
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2Pb2+ is low solubility with Cl- so they react and [Cl-] decreases
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2OThe molar solubility is the number moles per litre and therefore does not change when more water is added.
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl
AgCl is a solid that the solution is already saturated with and it does not change the solubility
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl none none
Increase Temperature
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl none none
Increase Temperature
Shifts to the right and increases the ksp
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl none none
Increase Temperature Increase Increase
Decrease Temperature
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl none none
Increase Temperature Increase Increase
Decrease Temperature
Changing the Solubility of a Salt
energy + AgCl(s) ⇄ Ag+ + Cl-
Substance Added Effect on Molar Solubility Effect on Ksp AgNO3 Decrease none
NaCl Decrease none
Na2S Increase none
Pb(NO3)2 Increase none
H2O none none
AgCl none none
Increase Temperature Increase Increase
Decrease Temperature Decrease Decrease
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl Increase none
NaCl
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl Increase none
NaCl none none
Ca(OH)2
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl Increase none
NaCl none none
Ca(OH)2 none none
Increase Temperature
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl Increase none
NaCl none none
Ca(OH)2 none none
Increase Temperature Increase Increase
Decrease Temperature
Changing the Solubility of a Salt
Ca(OH)2(s) ⇄ Ca2+ + 2OH- Substance Added Effect on Molar Solubility Effect on Ksp Ca(NO3)2 Decrease none
Na2SO4 Increase none
NaOH Decrease none
HCl Increase none
NaCl none none
Ca(OH)2 none none
Increase Temperature Increase Increase
Decrease Temperature Decrease Decrease