I. Introduction to Acids & Bases Ch. 19 – Acids & Bases I. Introduction to Acids & Bases

Review – Acid Nomenclature

Review – Acid Nomenclature

Review – Naming Acids HCl Hydrochloric acid H2S Hydrosulfuric acid H2SO4 H2SO3 HNO3 HNO2 HBr Hydrochloric acid Hydrosulfuric acid Sulfuric acid Sulfurous acid Nitric acid Nitrous acid Hydrobromic acid

A. Properties ACIDS BASES electrolytes  electrolytes sour taste bitter taste turn litmus red turn litmus blue react with metals to form H2 gas slippery feel vinegar, milk, soda, apples, citrus fruits ammonia, lye, antacid, baking soda

HF H3PO4 H2SO4 B. Definitions monoprotic triprotic diprotic polyprotic Monoprotic – an acid with one H+ Polyprotic – an acid with more than one H+ Diprotic – an acid with 2 H+ Triprotic – an acid with 3 H+ HF H3PO4 H2SO4 monoprotic triprotic diprotic polyprotic

HCl + H2O  H3O+ + Cl– B. Definitions – + Arrhenius Acids contain hydrogen Acids form hydronium ions (H3O+) in aqueous solution HCl + H2O  H3O+ + Cl– H Cl O – + acid

NaOH  Na+ + OH- B. Definitions Arrhenius Bases contain a hydroxide group Bases form hydroxide ions (OH-) in aqueous solution H2O NaOH  Na+ + OH- base

HCl + H2O  Cl– + H3O+ B. Definitions acid conjugate base base Brønsted-Lowry Acids are proton (H+) donors Bases are proton (H+) acceptors HCl + H2O  Cl– + H3O+ acid conjugate base base conjugate acid

HBr + NaOH  NaBr + H2O B. Definitions acid conjugate base base Brønsted-Lowry Conjugate Acids are the result after a base accepts a hydrogen ion Conjugate Bases are the result after an acid donates a hydrogen ion HBr + NaOH  NaBr + H2O acid conjugate base base conjugate acid

Amphoteric – can be an acid or a base B. Definitions H2O + HNO3  H3O+ + NO3– B A CA CB H2O + NH3  NH4+ + OH- A B CA CB Amphoteric – can be an acid or a base

Polyprotic – an acid with more than one H+ B. Definitions Give the conjugate base for each of the following: HF H3PO4 H3O+ F - H2PO4- H2O Polyprotic – an acid with more than one H+

Br - HSO4- CO32- HBr H2SO4 HCO3- B. Definitions Give the conjugate acid for each of the following: Br - HSO4- CO32- HBr H2SO4 HCO3-

B. Definitions Lewis Acids are electron pair acceptors Bases are electron pair donors Lewis base Lewis acid

C. Strength Strong Acid/Base 100% ionized in water strong electrolyte - + Strong Acid/Base 100% ionized in water strong electrolyte NaOH KOH RbOH CsOH Ca(OH)2 Ba(OH)2 HCl HNO3 H2SO4 HBr HI HClO4

C. Strength Weak Acid/Base does not ionize completely weak electrolyte - + HF CH3COOH H3PO4 H2CO3 HCN NH3

Ch. 19 – Acids & Bases II. pH (p. 644 – 658)

pH water equilibrium Pure water ionizes to a small extent to produce hydrogen ions and hydroxide ions According to LeChatlier’s principle if an acid is dissolved in water the equilibrium will shift to the left decreasing the hydroxide ion concentration. If a base is dissolved in water this decreases the hydrogen ion concentration.

Self-Ionization of Water A. Ionization of Water H2O (l)+ H2O (l) H3O+(aq)+ OH- (aq) Self-Ionization of Water

Kw = [H3O+][OH-] = 1.0  10-14 A. Ionization of Water Ion Product Constant for Water The ion production of water, Kw = [H3O+][OH–] Pure water contains equal concentrations of H+ and OH– ions, so [H3O+] = [OH–] For all aqueous solutions, the product of the hydrogen-ion concentration and the hydroxide-ion concentration equals 1.0 x 10-14

A. Ionization of Water Find the hydroxide ion concentration of 3.0  10-2 M HCl. HCl → H+ + Cl- 3.0  10-2M 3.0  10-2M [H3O+][OH-] = 1.0  10-14 [3.0  10-2][OH-] = 1.0  10-14 [OH-] = 3.3  10-13 M

A. Ionization of Water Find the hydronium ion concentration of 1.4  10-3 M Ca(OH)2. Ca(OH)2 → Ca2+ + 2 OH- 1.4  10-3M 2.8  10-3M [H3O+][OH-] = 1.0  10-14 [H3O+][2.8  10-3] = 1.0  10-14 [H3O+] = 3.6  10-12 M

pouvoir hydrogène (Fr.) B. pH Scale 14 7 INCREASING ACIDITY INCREASING BASICITY NEUTRAL pH = -log[H3O+] pouvoir hydrogène (Fr.) “hydrogen power”

pH of Common Substances B. pH Scale pH of Common Substances

pH = -log[H3O+] pOH = -log[OH-] pH + pOH = 14 B. pH Scale pH = -log[H3O+] pOH = -log[OH-] pH + pOH = 14

B. pH Scale What is the pH of 0.050 M HNO3? pH = -log[H3O+] Acidic or basic? Acidic

B. pH Scale What is the pH of 0.050 M Ba(OH)2? [OH-] = 0.100 M pOH = -log[OH-] pOH = -log[0.100] pOH = 1.00 pH = 13.00 Acidic or basic? Basic

B. pH Scale What is the molarity of HBr in a solution that has a pOH of 9.60? pH + pOH = 14 pH + 9.60 = 14 pH = 4.40 pH = -log[H3O+] 4.40 = -log[H3O+] -4.40 = log[H3O+] [H3O+] = 4.0  10-5 M HBr Acidic