1. SA/SB Titration Initial pH: pts A and E: A = all SA; B = all SB
Pre-equiv: pts B and F: B = xs SA; F = xs SB
Equiv pt: pt C: pH = 7
Post-equiv: pts D and G: D = xs SB; G = xs SA

2. WA/SB Titration
Initial pH: pts A and E: A = all WA; B = all WB (ICE box)
Pre-equiv: pts B and F: buffer (modified ICE)
Equiv pt: pts C and G: switcheroo (use ICE for conjugate)
Post-equiv: pts D and G: D = xs SB; G = xs SA

3. WA/SB Problem
Titration of 40.0 mL of M HPr (propanoic acid, CH3CH2CO2H) with M NaOH.
Ka HPr = 1.3x10-5
How many mL NaOH to reach equiv pt?
Calc initial pH.

4. pH for pre-equiv pt
Calc pH when add 10.0 mL of NaOH.

5. pH at equiv pt = “switcheroo”
Calc pH at equiv pt.

6. pH post-equiv pt
Calc pH when add 60.0 mL of M NaOH.

7. Additional Problem
Calculate pH for the titration of 25.0 mL of M ethylamine (CH3CH2NH2) with 0.05 M HCl.
Kb for ethylamine = 6.4x10-4
Identify the analyte and the titrant.
How many mL of HCl must be added to reach equiv pt?
Calc initial pH.
Calc pH if add 5.00 mL of HCl.
Calc pH at equiv pt.
Calc pH if add 60.0 mL of HCl.

8. Solubility Equilibria
Looks at equil between (s) and ions (salts dissolved in water at saturation point)
Ex. NaCl (s) Na+ (aq) + Cl- (aq)
When put salt in water, it dissolves.
As ions build up, they can reform the salt.
At some point, establish eq = saturation point.
Since we have equil, we can write a K expression. Ksp (solubility product constant)
Ksp = [Na+][Cl-]

9. Ksp Ksp tells about how soluble or not a salt is-explain
Solubility is the same as [ ] so for NaCl,
NaCl (s) Na+ (aq) + Cl- (aq)
if 1 M, then …
if S, then …
Ksp= [Na+][Cl-] = (S)(S) = S2
Solubility, S = √Ksp = M units

10. If AgBr (s) has Ksp = 1.6x10-10 at 25oC, what is
solubility in M?
2. What does that # mean in words?

11. Write Ksp expression for magnesium bromide (s) dissolving in water in terms of [ ] and S.
Calculate Ksp if, at 25oC, S = M.

12. Which is more soluble AgCl or NiS. Ksp AgCl = 1
Which is more soluble AgCl or NiS? Ksp AgCl = 1.6x10-10 Ksp NiS = 3x10-21 Which is more soluble AgCl or Ba(OH)2? Ksp AgCl = 1.6x10-10 Ksp Ba(OH)2 = 5x10-3

13. Common Ion Effect? Calc S of CaF2 (Ksp = 4x10-11).
Will S be affected if add NaF? Explain.
Calc S of CaF2 in a solution of M NaF.

14. Does pH affect solubility?
Ba(OH)2 (s) Ba2+ (aq) + 2 OH- (aq)
If add HCl (↓pH), would solubility change?
What about adding NaOH?

15. Consider NaNO2 (s) Na+ (aq) + NO2- (aq)
If add HCl would solubility change?
Would MgBr2 be more soluble in acid or water?

16. Will ppt form? Compare Qsp to Ksp
If Qsp > Ksp, ppt will form
If Qsp < Ksp, no ppt
Will ppt form when 100. mL of 4x10-4 M Mg(NO3)2 is mixed with 100. mL of 2x10-4 M NaOH? Ksp Mg(OH)2 = 1.8x10-11