AcidBase Equilibria and Solubility Equilibria Chapter 16 1
![Acid-Base Equilibria and Solubility Equilibria Chapter 16 1 Copyright © The Mc. Graw-Hill Companies, Acid-Base Equilibria and Solubility Equilibria Chapter 16 1 Copyright © The Mc. Graw-Hill Companies,](https://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-1.jpg)
Acid-Base Equilibria and Solubility Equilibria Chapter 16 1 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.
![The common ion effect is the shift in equilibrium caused by the addition of The common ion effect is the shift in equilibrium caused by the addition of](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-2.jpg)
The common ion effect is the shift in equilibrium caused by the addition of a compound having an ion in common with the dissolved substance. The presence of a common ion suppresses the ionization of a weak acid or a weak base. Consider mixture of CH 3 COONa (strong electrolyte) and CH 3 COOH (weak acid). CH 3 COONa (s) Na+ (aq) + CH 3 COO- (aq) CH 3 COOH (aq) H+ (aq) + CH 3 COO- (aq) common ion 2
![Consider mixture of salt Na. A and weak acid HA. Na. A (s) Na+ Consider mixture of salt Na. A and weak acid HA. Na. A (s) Na+](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-3.jpg)
Consider mixture of salt Na. A and weak acid HA. Na. A (s) Na+ (aq) + A- (aq) HA (aq) H+ (aq) + A- (aq) [H+] = Ka [HA] [A-] -log [H+] = -log Ka - log [HA] [A-] -] [A -log [H+] = -log Ka + log [HA] [A-] p. H = p. Ka + log [HA] [H+][A-] Ka = [HA] Henderson-Hasselbalch equation p. H = p. Ka + log [conjugate base] [acid] p. Ka = -log Ka 3
![What is the p. H of a solution containing 0. 30 M HCOOH and What is the p. H of a solution containing 0. 30 M HCOOH and](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-4.jpg)
What is the p. H of a solution containing 0. 30 M HCOOH and 0. 52 M HCOOK? Mixture of weak acid and conjugate base! HCOOH (aq) H+ (aq) + HCOO- (aq) Initial (M) Change (M) Equilibrium (M) Common ion effect 0. 30 – x 0. 30 0. 52 + x 0. 52 HCOOH p. Ka = 3. 77 0. 30 0. 00 0. 52 -x +x +x 0. 30 - x x 0. 52 + x [HCOO-] p. H = p. Ka + log [HCOOH] [0. 52] = 4. 01 p. H = 3. 77 + log [0. 30] 4
![A buffer solution is a solution of: 1. A weak acid or a weak A buffer solution is a solution of: 1. A weak acid or a weak](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-5.jpg)
A buffer solution is a solution of: 1. A weak acid or a weak base and 2. The salt of the weak acid or weak base Both must be present! A buffer solution has the ability to resist changes in p. H upon the addition of small amounts of either acid or base. Consider an equal molar mixture of CH 3 COOH and CH 3 COONa Add strong acid H+ (aq) + CH 3 COO- (aq) CH 3 COOH (aq) Add strong base OH- (aq) + CH 3 COOH (aq) CH 3 COO- (aq) + H 2 O (l) 5
![HCl H+ + Cl. HCl + CH 3 COO- CH 3 COOH + Cl- HCl H+ + Cl. HCl + CH 3 COO- CH 3 COOH + Cl-](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-6.jpg)
HCl H+ + Cl. HCl + CH 3 COO- CH 3 COOH + Cl- 6
![Which of the following are buffer systems? (a) KF/HF (b) KBr/HBr, (c) Na 2 Which of the following are buffer systems? (a) KF/HF (b) KBr/HBr, (c) Na 2](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-7.jpg)
Which of the following are buffer systems? (a) KF/HF (b) KBr/HBr, (c) Na 2 CO 3/Na. HCO 3 (a) KF is a weak acid and F- is its conjugate base buffer solution (b) HBr is a strong acid not a buffer solution (c) CO 32 - is a weak base and HCO 3 - is its conjugate acid buffer solution 7
![Calculate the p. H of the 0. 30 M NH 3/0. 36 M NH Calculate the p. H of the 0. 30 M NH 3/0. 36 M NH](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-8.jpg)
Calculate the p. H of the 0. 30 M NH 3/0. 36 M NH 4 Cl buffer system. What is the p. H after the addition of 20. 0 m. L of 0. 050 M Na. OH to 80. 0 m. L of the buffer solution? NH 4+ (aq) H+ (aq) + NH 3 (aq) [NH 3] p. H = p. Ka + log [NH 4+] start (moles) end (moles) p. Ka = 9. 25 [0. 30] p. H = 9. 25 + log = 9. 17 [0. 36] 0. 024 0. 029 0. 001 NH 4+ (aq) + OH- (aq) H 2 O (l) + NH 3 (aq) 0. 028 0. 025 final volume = 80. 0 m. L + 20. 0 m. L = 100 m. L [NH 4 +] = 0. 028 0. 025 [NH 3] = 0. 10 [0. 25] = 9. 20 p. H = 9. 25 + log [0. 28] 8
![Chemistry In Action: Maintaining the p. H of Blood Red blood cells in a Chemistry In Action: Maintaining the p. H of Blood Red blood cells in a](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-9.jpg)
Chemistry In Action: Maintaining the p. H of Blood Red blood cells in a capillary 9
![Titrations (Review) In a titration a solution of accurately known concentration is added gradually Titrations (Review) In a titration a solution of accurately known concentration is added gradually](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-10.jpg)
Titrations (Review) In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration until the chemical reaction between the two solutions is complete. Equivalence point – the point at which the reaction is complete Indicator – substance that changes color at (or near) the equivalence point Slowly add base to unknown acid UNTIL The indicator changes color (pink) 10
![Alternative Method of Equivalence Point Detection monitor p. H 11 Alternative Method of Equivalence Point Detection monitor p. H 11](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-11.jpg)
Alternative Method of Equivalence Point Detection monitor p. H 11
![Strong Acid-Strong Base Titrations Na. OH (aq) + HCl (aq) H 2 O (l) Strong Acid-Strong Base Titrations Na. OH (aq) + HCl (aq) H 2 O (l)](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-12.jpg)
Strong Acid-Strong Base Titrations Na. OH (aq) + HCl (aq) H 2 O (l) + Na. Cl (aq) OH- (aq) + H+ (aq) H 2 O (l) 12
![Weak Acid-Strong Base Titrations CH 3 COOH (aq) + Na. OH (aq) CH 3 Weak Acid-Strong Base Titrations CH 3 COOH (aq) + Na. OH (aq) CH 3](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-13.jpg)
Weak Acid-Strong Base Titrations CH 3 COOH (aq) + Na. OH (aq) CH 3 COONa (aq) + H 2 O (l) CH 3 COOH (aq) + OH- (aq) CH 3 COO- (aq) + H 2 O (l) At equivalence point (p. H > 7): CH 3 COO- (aq) + H 2 O (l) OH- (aq) + CH 3 COOH (aq) 13
![Strong Acid-Weak Base Titrations HCl (aq) + NH 3 (aq) NH 4 Cl (aq) Strong Acid-Weak Base Titrations HCl (aq) + NH 3 (aq) NH 4 Cl (aq)](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-14.jpg)
Strong Acid-Weak Base Titrations HCl (aq) + NH 3 (aq) NH 4 Cl (aq) H+ (aq) + NH 3 (aq) NH 4 Cl (aq) At equivalence point (p. H < 7): NH 4+ (aq) + H 2 O (l) NH 3 (aq) + H+ (aq) 14
![Exactly 100 m. L of 0. 10 M HNO 2 are titrated with a Exactly 100 m. L of 0. 10 M HNO 2 are titrated with a](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-15.jpg)
Exactly 100 m. L of 0. 10 M HNO 2 are titrated with a 0. 10 M Na. OH solution. What is the p. H at the equivalence point ? start (moles) 0. 01 HNO 2 (aq) + OH- (aq) NO 2 - (aq) + H 2 O (l) end (moles) 0. 01 Final volume = 200 m. L [NO 2 -] = = 0. 05 M 0. 200 NO 2 - (aq) + H 2 O (l) OH- (aq) + HNO 2 (aq) Initial (M) Change (M) Equilibrium (M) 0. 05 0. 00 -x +x +x 0. 05 - x x x [OH-][HNO 2] x 2 -11 = 2. 2 x 10 Kb = = [NO 2 -] 0. 05 -x 0. 05 – x 0. 05 x 1. 05 x 10 -6 = [OH-] p. OH = 5. 98 p. H = 14 – p. OH = 8. 02 15
![Acid-Base Indicators HIn (aq) H+ (aq) + In- (aq) [HIn] 10 Color of acid Acid-Base Indicators HIn (aq) H+ (aq) + In- (aq) [HIn] 10 Color of acid](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-16.jpg)
Acid-Base Indicators HIn (aq) H+ (aq) + In- (aq) [HIn] 10 Color of acid (HIn) predominates [In ] [HIn] -) predominates Color of conjugate base (In 10 [In-] 16
![Solutions of Red Cabbage Extract p. H 17 Solutions of Red Cabbage Extract p. H 17](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-17.jpg)
Solutions of Red Cabbage Extract p. H 17
![The titration curve of a strong acid with a strong base. 18 The titration curve of a strong acid with a strong base. 18](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-18.jpg)
The titration curve of a strong acid with a strong base. 18
![Which indicator(s) would you use for a titration of HNO 2 with KOH ? Which indicator(s) would you use for a titration of HNO 2 with KOH ?](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-19.jpg)
Which indicator(s) would you use for a titration of HNO 2 with KOH ? Weak acid titrated with strong base. At equivalence point, will have conjugate base of weak acid. At equivalence point, p. H > 7 Use cresol red or phenolphthalein 19
![Solubility Equilibria Ag. Cl (s) Ag+ (aq) + Cl- (aq) Ksp = [Ag+][Cl-] Ksp Solubility Equilibria Ag. Cl (s) Ag+ (aq) + Cl- (aq) Ksp = [Ag+][Cl-] Ksp](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-20.jpg)
Solubility Equilibria Ag. Cl (s) Ag+ (aq) + Cl- (aq) Ksp = [Ag+][Cl-] Ksp is the solubility product constant Mg. F 2 (s) Mg 2+ (aq) + 2 F- (aq) Ksp = [Mg 2+][F-]2 Ag 2 CO 3 (s) 2 Ag+ (aq) + CO 32 - (aq) Ksp = [Ag+]2[CO 32 -] Ca 3(PO 4)2 (s) 3 Ca 2+ (aq) + 2 PO 43 - (aq) Ksp = [Ca 2+]3[PO 43 -]2 Dissolution of an ionic solid in aqueous solution: Q < Ksp Unsaturated solution Q = Ksp Saturated solution Q > Ksp Supersaturated solution No precipitate Precipitate will form 20
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![Molar solubility (mol/L) is the number of moles of solute dissolved in 1 L Molar solubility (mol/L) is the number of moles of solute dissolved in 1 L](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-22.jpg)
Molar solubility (mol/L) is the number of moles of solute dissolved in 1 L of a saturated solution. Solubility (g/L) is the number of grams of solute dissolved in 1 L of a saturated solution. 22
![What is the solubility of silver chloride in g/L ? Initial (M) Ag. Cl What is the solubility of silver chloride in g/L ? Initial (M) Ag. Cl](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-23.jpg)
What is the solubility of silver chloride in g/L ? Initial (M) Ag. Cl (s) Ag+ (aq) + Cl- (aq) 0. 00 Change (M) Equilibrium (M) [Ag+] = 1. 3 x 10 -5 M +s +s s s [Cl-] = 1. 3 x 10 -5 M Ksp = 1. 6 x 10 -10 Ksp = [Ag+][Cl-] Ksp = s 2 s = K sp s = 1. 3 x 10 -5 mol Ag. Cl 143. 35 g Ag. Cl Solubility of Ag. Cl = x = 1. 9 x 10 -3 g/L 1 L soln 1 mol Ag. Cl 23
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![If 2. 00 m. L of 0. 200 M Na. OH are added to If 2. 00 m. L of 0. 200 M Na. OH are added to](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-25.jpg)
If 2. 00 m. L of 0. 200 M Na. OH are added to 1. 00 L of 0. 100 M Ca. Cl 2, will a precipitate form? The ions present in solution are Na+, OH-, Ca 2+, Cl-. Only possible precipitate is Ca(OH)2 (solubility rules). Is Q > Ksp for Ca(OH)2? [Ca 2+]0 = 0. 100 M [OH-]0 = 4. 0 x 10 -4 M Q = [Ca 2+]0[OH-]02 = 0. 10 x (4. 0 x 10 -4)2 = 1. 6 x 10 -8 Ksp = [Ca 2+][OH-]2 = 8. 0 x 10 -6 Q < Ksp No precipitate will form 25
![What concentration of Ag is required to precipitate ONLY Ag. Br in a solution What concentration of Ag is required to precipitate ONLY Ag. Br in a solution](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-26.jpg)
What concentration of Ag is required to precipitate ONLY Ag. Br in a solution that contains both Br- and Cl- at a concentration of 0. 02 M? Ag. Br (s) Ag+ (aq) + Br- (aq) Ksp = 7. 7 x 10 -13 Ksp = [Ag+][Br-] -13 K 7. 7 x 10 sp -11 M = = 3. 9 x 10 [Ag+] = 0. 020 [Br-] Ag. Cl (s) Ag+ (aq) + Cl- (aq) [Ag+] = Ksp = 1. 6 x 10 -10 Ksp = [Ag+][Cl-] Ksp 1. 6 x 10 -10 -9 M = = 8. 0 x 10 0. 020 [Cl-] 3. 9 x 10 -11 M < [Ag+] < 8. 0 x 10 -9 M Ag. Cl Ag. Br 26
![The Common Ion Effect and Solubility The presence of a common ion decreases the The Common Ion Effect and Solubility The presence of a common ion decreases the](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-27.jpg)
The Common Ion Effect and Solubility The presence of a common ion decreases the solubility of the salt. What is the molar solubility of Ag. Br in (a) pure water and (b) 0. 0010 M Na. Br? Na. Br (s) Na+ (aq) + Br- (aq) Ag. Br (s) Ag+ (aq) + Br- (aq) [Br-] = 0. 0010 M Ksp = 7. 7 x 10 -13 Ag. Br (s) Ag+ (aq) + Br- (aq) s 2 = Ksp [Ag+] = s s = 8. 8 x 10 -7 [Br-] = 0. 0010 + s 0. 0010 Ksp = 0. 0010 x s s = 7. 7 x 10 -10 27
![p. H and Solubility • • • The presence of a common ion decreases p. H and Solubility • • • The presence of a common ion decreases](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-28.jpg)
p. H and Solubility • • • The presence of a common ion decreases the solubility. Insoluble bases dissolve in acidic solutions Insoluble acids dissolve in basic solutions remove add Mg(OH)2 (s) Mg 2+ (aq) + 2 OH- (aq) Ksp = [Mg 2+][OH-]2 = 1. 2 x 10 -11 Ksp = (s)(2 s)2 = 4 s 3 = 1. 2 x 10 -11 s = 1. 4 x 10 -4 M [OH-] = 2 s = 2. 8 x 10 -4 M p. OH = 3. 55 p. H = 10. 45 At p. H less than 10. 45 Lower [OH-] OH- (aq) + H+ (aq) H 2 O (l) Increase solubility of Mg(OH)2 At p. H greater than 10. 45 Raise [OH-] Decrease solubility of Mg(OH)2 28
![Complex Ion Equilibria and Solubility A complex ion is an ion containing a central Complex Ion Equilibria and Solubility A complex ion is an ion containing a central](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-29.jpg)
Complex Ion Equilibria and Solubility A complex ion is an ion containing a central metal cation bonded to one or more molecules or ions. Co 2+ (aq) + 4 Cl- (aq) Co. Cl 24 (aq) The formation constant or stability constant (Kf) is the equilibrium constant for the complex ion formation. Co(H 2 O)2+ 6 Co. Cl 24 HCl Kf = [Co. Cl 42 - ] [Co 2+][Cl-]4 Kf stability of complex 29
![Effect of Complexation on Solubility Ag. NO Add NH 3 + Na. Cl 3 Effect of Complexation on Solubility Ag. NO Add NH 3 + Na. Cl 3](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-30.jpg)
Effect of Complexation on Solubility Ag. NO Add NH 3 + Na. Cl 3 Ag(NH Ag. Cl 3)2+ 30
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![Qualitative Analysis of Cations 33 Qualitative Analysis of Cations 33](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-33.jpg)
Qualitative Analysis of Cations 33
![Flame Test for Cations lithium sodium potassium copper 34 Flame Test for Cations lithium sodium potassium copper 34](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-34.jpg)
Flame Test for Cations lithium sodium potassium copper 34
![Chemistry In Action: How an Eggshell is Formed Ca 2+ (aq) + CO 32 Chemistry In Action: How an Eggshell is Formed Ca 2+ (aq) + CO 32](http://slidetodoc.com/presentation_image_h/1d890f9871f75dae50591b1fbed0110d/image-35.jpg)
Chemistry In Action: How an Eggshell is Formed Ca 2+ (aq) + CO 32 - (aq) Ca. CO 3 (s) carbonic CO 2 (g) + H 2 O (l) H 2 CO 3 (aq) anhydrase H 2 CO 3 (aq) H+ (aq) + HCO 3 - (aq) H+ (aq) + CO 32 - (aq) electron micrograph 35
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