PP 21: Acids & Bases Drill: Rxn: 1 A + 2 B 1 C + 1 D . (Kc = 2.0 x 10-12) Calculate the equilibrium concentrations of each species when a solution is made with 1.0 M A & 1.0 M B Acids & Bases Properties of Acids: Sour taste, Change color of dyes, Conduct electricity in solution, React with many metals, React with bases to form salts Properties of Bases: Bitter taste, Feel slippery, Change color of dyes, Conduct electricity in solution, React with acids to form salts Types of acids & bases: Arrhenius acids & bases Acids: release H+ or H3O+ in solution Bases: release OH- in solution Bronsted/Lawry acids & bases: Acid: Proton donor Base: Proton Acceptor General HA H+ + AMOH M+ + OH- General HA + H2O H3O+ + AAcid base CA CB NH3 + H2O NH4+ + OHBase acid CA CB Specific HCl H+ + ClKOH K+ + OHSpecific HI + H2O H3O+ + IAcid base CA CB NH3 + H2O NH4+ + OHBase acid CA CB Lewis Acids & Bases: BF3 + NH3 H3N-BF3 Acid: Electron Acceptor Base: Electron Donor Common Names: H+ H3O+ H OH NH3 NH4+ Hydrogen ion Hydronium ion Hydride ion Hydroxide ion Ammonia Ammonium ion Amphiprotism: Can act like an acid or a base or can donate or accept protons Naming Acids: All acids are H-anion o If the anion is: -ides -ates -ites hydro___ic acids ___ic acids ___ous acids Naming bases: Almost all bases are metal hydroxides Name by normal method Ammonia (NH3) as well as many amines are bases Drill: Name each of the following: KOH HBr Al(OH)3 H2CO3 HClO4 Strong Acids or Bases: Strong acids or bases ionize 100 % in solution Weak acids or bases ionize <100 % in solution Strong Acids: HClO 4 H2SO4 HNO3 HCl HBr HI Perchloric acid Sulfuric acid Nitric acid Hydrochloric acid Hydrobromic acid Hydroiodic acid Strong Bases - Column IA meatl hydrocides - Lower 3 of column II metal Hudrodrxides Determining H+ or OH- concentrations in strong acids & bases: 0.10 M Strong Acids ionize 100%: HA H+ + A0.10 – all 0.10 0.10 0.10 M Strong Bases ionize 100%: MOH 0.10 – all M+ + OH0.10 0.10 Binary Acids: Acids containing only 2 elements HCl hydrochloric acid HI hydroiodic acid Ternary Acids: Acids containing 3 elements H2SO4 sulfuric acid HNO3 nitric acid Monoprotic Acids: Acids containing only 1 ionizable hydrogen HBr hydrobromic acid HC2H3O2 acetic acid Polyprotic Acids: Acids containing 2 or more ionizable hydrogen H2SO4 sulfuric acid H3PO4 phosphoric acid Diprotic Acids: Acids containing 2 ionizable hydrogen H2SO4 sulfuric acid H2CO3 carbonic acid Triprotic Acids: Acids containing 3 ionizable hydrogen H3PO4 phosphoric acid H3AsO4 arsenic acid Monohydroxic Acids: Acids containing only 1 ionizable hydroxide KOH potassium hydroxide NaOH sodium hydroxide NH3 Neutralization Reaction: A reaction between an acid & a base making salt & H2O · General Example: HA(aq) + MOH(aq) MA(aq) + H2O(l) · General Example: HCl(aq) + NaOH(aq) NaCl(aq) + H2O(l) Drill: Identify the acid, the base, the conjugate acid, & the conjugate base in the following reaction: General example: HCO3- + H2O H2CO3 + OH- pH: The negative log of the hydrogen or hydronium ion concentration pH = -log[H+] pOH = -log[OH-] Calculate the pH of each of the following: [H+] = 0.040 M [HCl] = 0.0025 M [HBr] = 0.080 M Calculate the pOH of each of the following: [OH-] = 0.030 M [KOH] = 0.0025 M [NaOH] = 4.0 x 10-7 M Standard Solution: A solution with known concentration Titration: A method of determining the concentration of one solution by reacting it with a standard solution Titration Fact: When titrating acids against bases, the end point of the titration is at the equivalence point No changes will be observed when titrating acids against bases; thus, one must use an indicator to see changes Equivalence Point: The point where the concentrations of the two solutions in the titration are equal Acid/Base Equivalence Point: The point where the H+ concentration is equal to the OH- concentration Indicator: An organic dye that changes color when the pH changes Titration Formula for monoprotic solutions: MAVA = MBVB Molarity (M): Moles of solute per liter of solution Problem: Calculate the molarity of 25.0 mL HCl when it’s titrated to its equivalence point with 50.0 mL 0.200 M NaOH: Dilution Formula: M1V1 = M2V2 Problems: Calculate the mL of 16.0 M HNO3 it takes to make 4.0 L of 0.100 M HNO3 Calculate the mL of 12.5 M HCl required to make 2.5 L of 0.200 M HCl Normality (N): Number of moles of hydrogen or hydroxide ions per liter of solution Titration Formula for Acid/Base: NAVA = NBVB Elliot’s Rule: #HMAVA = #OHMBVB Problems: Calculate the molarity of 30.0 mL H2CO3 when it’s titrated to its equivalence point with · 75.0 mL 0.200 M NaOH Calculate the molarity of 40.0 mL H3PO4 when it’s titrated to its equivalence point with 30.0 mL 0.20 M Ba(OH)2 Calculate the volume of 0.250 M HCl needed to titrate 50.00 mL 0.200 M NaOH to its equivalence point Calculate the molarity 25.0 mL H3PO4 that neutralizes 50.00 mL 0.200 M Ca(OH)2 to its equivalence point Titration Curve: Strong acid vs strong base Titration Curve: Strong acid vs strong base