Transcript

Example: Ions

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Acids HCl, HL, H2SO4 Contains ionizable H+ in H2O H+ is hydrated H3O+ = hydronium ion sour Strong or weak Blue -> red Acids react with bases to form a salt and water Oxyacids formed when reaction of nonmetal oxide and water SO2+H2O -> H2SO3

Bases Tums, NaOH (Lye) NH3 Contains ionizable OHbitter Strong or weak Red -> blue Bases react with acids to form salt + H2O formed by reaction of metal oxide with water Na2O + H2O -> 2 NaOH

Salts NaCl, KCl, MgCl2 Dissociates in aqueous solutions salty STRONG! ---

f Taste: Electrolyte strength: Effects on Litmus Paper: Reactions:

Formation:

NaOH + HCl -> H2O + NaCL

Forms from reaction of an acid and a base

(Oxyacids: H2SO4, H3PO4, HNO3) Arrhenius Acids and Bases: -Acid: produces H3O+ in aqueous solution HA + H2O <-> H3O+ + A- (NOTE: “A” is a variable) -strong acids: ionize 100% (strong electrolytes) ( HCl HClO4 HBr HI HNO3 H2SO4 ) + H2O -> H3O+ + NO3-weak acids: ionize slightly (weak electrolytes) HC2H3O2 (CH3COOH) <-> H3O+ = C2H3O2 -Base: produces OH- in aqueous solution MOH <-> M++OH- (M = Metal) -strong base: dissociates 100% group one metal hydroxides and some of the group 2 metal hydroxides (Ca, Sr, Ba) KOH -weak base: ionize slightly NH3 + H2O <-> NH4+ + OHBrØnsted-Lowry Acids and Bases: -Acids: a molecule or ion that is a proton (H+) donor all Arrhenius acids are BrØnsted Lowery acids where water is the H+ acceptor -Base: a molecule or ion that is a proton (H+) acceptor -EX: (conjugate acids and bases go “back the other direction”)

-Monoprotic Acids: an acid that can only donate one proton per molecule (HCl, HNO3, HClO4) -Polyprotic Acids: and acid that can donate mere than one proton per molecule (only 1 at a time)

ion or molecule that accepts an electron pair to form a covalent bond (all transition metals are Lewis acids) -Base: an atom. SO2 -sulfur dioxide produced from burning of coal and oil will be converted to sulfur trioxide which reacts with water in the atmosphere to produce sulfuric acid SO2+SO3+H2O -> H2SO4 Chapter 15: -Self-Ionization of Water: two water molecules produce a hydronium ion and a hydroxide ion by the transfer of a proton -Equation: H2O + H2O <-> H3O+ + OH.(VERY weak electrolyte) -Concentrations of Hydronium and Hydroxide Ions: [H3O+] = [OH-] = 1.0 x 10-7) = 1.0000007 will ionize) Neutral.producer Proton (H+) acceptor Electron pain donor Conjugate Acids and Bases: -base: the species that remains after a BrØnsted-Lowry acid has given up a proton -acid: the species that is formed when a BL base gains a proton Ex: -Strength of Conjugate Acids and Bases: * strong acid = weak conjugate base * weak acid = strong conjugate base Neutralization Reactions: -the reaction of hydronium ions and hydroxide ions to form water molecules -OH.Lewis Acids and Bases: -Acid: an atom. NO2.+ H+ <-> H2O (l) -salt: an ionic compound composed of a cation from a base and an anion from an acid Acid Rain: -Gases that can cause acid rain: NO.0 x 10-14 at 25oC -You always will get the same Kw but you have different ways of getting there .0 x 10-7)(1. Acidic and Basic Solutions: -Acidic: [H3O] > [OH] -Neutral: [H3O] = [OH] -Basic: [H3O] < [OH] Concentration constant of water: (Kw) -Kw= [H3O] [OH] = 1. ion or molecule that donates an electron pair to form a covalent bond Types of Acid/Base Arrhenius BrØnsted-Lowry Lewis Acid H3O+ producer Proton (H+) producer Electron pair acceptor Base OH.0 x 10-7M (for 1 L .0 x 10-14 ALWAYS -Kw= (1. CO2.

pH = -log[H3O] pOH = -log [OH-] pH = pOH = 14 (see above) pH --(14-pH) pOH –(10(-pOH)) [OH-] –(1.0 x 10-14/[OH-])  [H3O+] –(-log[H3O]) pH Indicators and pH meters: -pH meters and indicators tell concentration of a solution -the range over which an indicator changes color is called its transition interval Titration: -“goal” to find concentration of unknown solution -stop adding when completely reacted (moles are equal) = end point use indicator to show -equivalence point: solutions in chemically equivalent quantities -end point: indicator changes color (must have correct indicator) -the solution containing a precisely known concentration of a solute is called a standard solution The Math: -only use <-> when you have a weak acid and base -end point bromythal blue = pH 7 = equivalence point in strong acid and strong base (green) -solid metals reacting with acids give off H2 and salt -phosphoric acid has three “steps” – 3 hydrogens to lose 1) find moles unknown: molarity x volume = moles 2) find the moles of unknown (balanced equation): (mol known)(mol ratio) = mols unknown 3) find molarity or unknown: mols/liters .