(Benjamin, Chapt. 3) David Reckhow CEE 680 #9 1 In-class - PowerPoint PPT Presentation

Print version Updated: 5 February 2020 Lecture #9 Acids & Bases: Analytical Solutions with simplifying assumptions III (Stumm & Morgan, Chapt.3 ) (Benjamin, Chapt. 3) David Reckhow CEE 680 #9 1

In-class Practice Other UNISA students: Nomcebo. Phumlile,  10 -4 M Hydrofluoric Acid Kelebogile, Ngonidzashe, Sikelelwa, Umhle, Pfano,  UMass: JQ & Ian Liberty  UNISA: Godfrey  10 -2 M Phenol  UMass: Cielo, Alvin, Chris Please pick one; you  UNISA: Hezron & Naledi; Alfred & Ronald; Olayemi may work in groups  10 -3 M Carbonic Acid  UMass: Laura, Isaac, Bridgette  UNISA: ???  10 -4 M Sulfuric Acid  UNISA: Niall David Reckhow CEE 680 #9 2

NAME EQUILIBRIA pKa HClO4 = H+ + ClO4- Perchloric acid -7 STRONG HCl = H+ + Cl- Hydrochloric acid -3 H2SO4= H+ + HSO4- Sulfuric acid -3 (&2) ACIDS HNO3 = H+ + NO3- Nitric acid -0 H3O+ = H+ + H2O Hydronium ion 0 CCl3COOH = H+ + CCl3COO- 0.70 Trichloroacetic acid HIO3 = H+ + IO3- Iodic acid 0.8 CHCl2COOH = H+ + CHCl2COO- 1.48 Dichloroacetic acid HSO4- = H+ + SO4-2 2 Bisulfate ion H3PO4 = H+ + H2PO4- Phosphoric acid 2.15 (&7.2,12.3) Fe(H2O)6+ 3 = H+ + Fe(OH)(H2O)5+ 2 2.2 (&4.6) Ferric ion CH2ClCOOH = H+ + CH2ClCOO- 2.85 Chloroacetic acid C6H4(COOH)2 = H+ + C6H4(COOH)COO- 2.89 (&5.51) o-Phthalic acid C3H5O(COOH)3= H+ + C3H5O(COOH)2COO- 3.14 (&4.77,6.4) Citric acid HF = H+ + F- 3.2 Hydrofluoric acid HCOOH = H + + HCOO- 3.75 Formic Acid C2H6N(COOH)2= H+ + C2H6N(COOH)COO- 3.86 (&9.82) Aspartic acid C6H4(OH)COOH = H+ + C6H4(OH)COO- 4.06 (&9.92) m-Hydroxybenzoic acid C2H4(COOH)2 = H+ + C2H4(COOH)COO- 4.16 (&5.61) Succinic acid C6H4(OH)COOH = H+ + C6H4(OH)COO- 4.48 (&9.32) p-Hydroxybenzoic acid HNO2 = H+ + NO2- Nitrous acid 4.5 FeOH(H2O)5+ 2 + H+ + Fe(OH)2(H2O)4+ Ferric Monohydroxide 4.6 CH3COOH = H+ + CH3COO- 4.75 Acetic acid Al(H2O)6+ 3 = H+ + Al(OH)(H2O)5+ 2 4.8 Aluminum ion David Reckhow CEE 680 #9 3

NAME FORMULA pKa C2H5COOH = H+ + C2H5COO- 4.87 Propionic acid H2CO3 = H+ + HCO3- Carbonic acid 6.35 (&10.33) H2S = H+ + HS- Hydrogen sulfide 7.02 (&13.9) H2PO4- = H+ + HPO4-2 7.2 Dihydrogen phosphate HOCl = H+ + OCl- 7.5 Hypochlorous acid Cu(H2O)6+ 2 = H+ + CuOH(H2O)5+ Copper ion 8.0 Zn(H2O)6+ 2 = H+ + ZnOH(H2O)5+ Zinc ion 8.96 B(OH)3 + H2O = H+ + B(OH)4- Boric acid 9.2 (&12.7,13.8) NH4+ = H+ + NH3 Ammonium ion 9.24 HCN = H+ + CN- 9.3 Hydrocyanic acid C6H4(OH)COO- = H+ + C6H4(O)COO-2 9.32 p-Hydroxybenzoic acid H4SiO4 = H+ + H3SiO4- Orthosilicic acid 9.86 (&13.1) C6H5OH = H+ + C6H5O- 9.9 Phenol C6H4(OH)COO- = H+ + C6H4(O)COO-2 9.92 m-Hydroxybenzoic acid Cd(H2O)6+ 2 = H+ + CdOH(H2O)5+ Cadmium ion 10.2 HCO3- = H+ + CO3-2 Bicarbonate ion 10.33 Mg(H2O)6+ 2 = H+ + MgOH(H2O)5+ Magnesium ion 11.4 HPO4-2 = H+ + PO4-3 Monohydrogen phosphate 12.3 Ca(H2O)6+ 2 = H+ + CaOH(H2O)5+ Calcium ion 12.5 H3SiO4- = H+ + H2SiO4-2 Trihydrogen silicate 12.6 HS- = H+ + S-2 Bisulfide ion 13.9 H2O = H+ + OH- Water 14.00 NH3 = H+ + NH2- Ammonia 23 OH- = H+ + O-2 Hydroxide 24 CH4 = H+ + CH3- Methane 34 David Reckhow CEE 680 #9 4

Guide to Simplified Acid/Base Solutions #1  Neutral + ] ≈ [ H K w  if C<10 -8  Acid Addition, C>10 -6.5  Acidic − + + 2 K K 4 K C + ≈ a a a [ H ]  if K a C > 10 -13 2 + ] ≈ [ H C  Strong Acid + 2 + C C 4 K + ≈ w [ H ]  if K a > 10C 2 + ] ≈ [ H K C  Weak Acid a + ] ≈ + [ H K C K  if C > 100K a a w David Reckhow CEE 680 #9 5

Weak Acid Domain David Reckhow CEE 680 #9 6

Strong Acid Domain David Reckhow CEE 680 #9 7

Acidic Solution Domain David Reckhow CEE 680 #9 8

Combined Acid Domains David Reckhow CEE 680 #9 9

NAME EQUILIBRIA pKa HClO4 = H+ + ClO4- Perchloric acid -7 STRONG HCl = H+ + Cl- Hydrochloric acid -3 H2SO4= H+ + HSO4- Sulfuric acid -3 (&2) ACIDS HNO3 = H+ + NO3- Nitric acid -0 H3O+ = H+ + H2O Hydronium ion 0 CCl3COOH = H+ + CCl3COO- 0.70 Trichloroacetic acid HIO3 = H+ + IO3- Iodic acid 0.8 CHCl2COOH = H+ + CHCl2COO- 1.48 Dichloroacetic acid HSO4- = H+ + SO4-2 2 Bisulfate ion H3PO4 = H+ + H2PO4- Phosphoric acid 2.15 (&7.2,12.3) Fe(H2O)6+ 3 = H+ + Fe(OH)(H2O)5+ 2 2.2 (&4.6) Ferric ion CH2ClCOOH = H+ + CH2ClCOO- 2.85 Chloroacetic acid C6H4(COOH)2 = H+ + C6H4(COOH)COO- 2.89 (&5.51) o-Phthalic acid C3H5O(COOH)3= H+ + C3H5O(COOH)2COO- 3.14 (&4.77,6.4) Citric acid HF = H+ + F- 3.2 Hydrofluoric acid HCOOH = H + + HCOO- 3.75 Formic Acid C2H6N(COOH)2= H+ + C2H6N(COOH)COO- 3.86 (&9.82) Aspartic acid C6H4(OH)COOH = H+ + C6H4(OH)COO- 4.06 (&9.92) m-Hydroxybenzoic acid C2H4(COOH)2 = H+ + C2H4(COOH)COO- 4.16 (&5.61) Succinic acid C6H4(OH)COOH = H+ + C6H4(OH)COO- 4.48 (&9.32) p-Hydroxybenzoic acid HNO2 = H+ + NO2- Nitrous acid 4.5 FeOH(H2O)5+ 2 + H+ + Fe(OH)2(H2O)4+ Ferric Monohydroxide 4.6 CH3COOH = H+ + CH3COO- 4.75 Acetic acid Al(H2O)6+ 3 = H+ + Al(OH)(H2O)5+ 2 4.8 Aluminum ion David Reckhow CEE 680 #9 10

NAME FORMULA pKa C2H5COOH = H+ + C2H5COO- 4.87 Propionic acid H2CO3 = H+ + HCO3- Carbonic acid 6.35 (&10.33) H2S = H+ + HS- Hydrogen sulfide 7.02 (&13.9) H2PO4- = H+ + HPO4-2 7.2 Dihydrogen phosphate HOCl = H+ + OCl- 7.5 Hypochlorous acid Cu(H2O)6+ 2 = H+ + CuOH(H2O)5+ Copper ion 8.0 Zn(H2O)6+ 2 = H+ + ZnOH(H2O)5+ Zinc ion 8.96 B(OH)3 + H2O = H+ + B(OH)4- Boric acid 9.2 (&12.7,13.8) NH4+ = H+ + NH3 Ammonium ion 9.24 HCN = H+ + CN- 9.3 Hydrocyanic acid C6H4(OH)COO- = H+ + C6H4(O)COO-2 9.32 p-Hydroxybenzoic acid H4SiO4 = H+ + H3SiO4- Orthosilicic acid 9.86 (&13.1) C6H5OH = H+ + C6H5O- 9.9 Phenol C6H4(OH)COO- = H+ + C6H4(O)COO-2 9.92 m-Hydroxybenzoic acid Cd(H2O)6+ 2 = H+ + CdOH(H2O)5+ Cadmium ion 10.2 HCO3- = H+ + CO3-2 Bicarbonate ion 10.33 Mg(H2O)6+ 2 = H+ + MgOH(H2O)5+ Magnesium ion 11.4 HPO4-2 = H+ + PO4-3 Monohydrogen phosphate 12.3 Ca(H2O)6+ 2 = H+ + CaOH(H2O)5+ Calcium ion 12.5 H3SiO4- = H+ + H2SiO4-2 Trihydrogen silicate 12.6 HS- = H+ + S-2 Bisulfide ion 13.9 H2O = H+ + OH- Water 14.00 NH3 = H+ + NH2- Ammonia 23 OH- = H+ + O-2 Hydroxide 24 CH4 = H+ + CH3- Methane 34 David Reckhow CEE 680 #9 11

 To next lecture DAR David Reckhow CEE 680 #9 12