Acid – Base Definitions versus H

1 1substance that [OH ]in waterAcid base DefinitionsArrheniusacid: base :substance that [H+](protons) in wateracid:Br nsted-Lowryprotondonor(to base )protonacceptor(from acid ) base :Johannes ThomasSvante1923 Gilbert N. acid : base :e pairacceptor(from a base )e pairdonor(to an acid )1923 Lewis1884HA(aq)+ H+(aq)A (aq)notHA(aq)+ H3O+(aq)+ H2O( )A (aq)H3O+ versus H+B-Ldefinition x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 14pH = < > [H3O+]pH[OH ]pHH+= < = log[H3O+][H3O+] = 10 pH log+ pOH= pHpKwS ren S rensenDanish(1868-1939)[H3O+] = x 10 9 MpH = = [H3O+] = 10 x 10 6 MpH0123456789101112 Alizarian yellow RThymolphthaleinPhenolphthaleinThymol blue ( base )Phenol redBromothymol blueChlorophenol redBromocresol greenMethyl orangeBromophenol blueThymol blue ( acid )

2 Methyl violetpH can be measured with indicatorsMeasuring pHH+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+ H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+H+ H+H+H+H+H+H+H+H+H+H+H+thin glass membranesolution of known pHAg/AgCl referencePt conductorand pH can be measured with indicatorsMeasuring pHB + H2O HB++ OH (CH3)3N trimethylamineCH3O methoxide ionHA + H2O A + H3O+ one H+, often firstneutralor + (andH) one lone-pair e (Lewis)neutralor ,often Nor Oacid(HA):HClhydrochloric acid H2SO4sulfuric acidH3PO3phosphorous acid HC2H3O2acetic acidNH4+ammonium ionHC7H5O2benzoic acidbase(B):NH3ammoniaCO32 carbonate ionC5H5 NpyridineN2H4hydrazineRecognizing Acids and Bases2Cl chlorideNO2 nitriteC2H3O2 acetatehydro_ic ous ic ide ite ateacid:CB:C5H5 NpyridineN2H4hydrazineCH3NH2methylamineC H3NH3+methylammoniumC5H5NH+pyridiniumHN2 H4+hydraziniumCA:HClhydrochloricacidHNO2 nitrousacidHC2H3O2aceticacidbase iumNH3ammoniaNH4+ammoniumRecognizing CBand CAFrom NameKbKapH acid /basereaction [H3O+] KAcid- base Equilibrium and pHHA+ H2O A + H3O+B+ H2O HB++ OH >> 1<< 1strongweakSASBWBWAK[H3O+][A ][HA]=[OH ][HB+][B]=Kcomplete ionization:7 common SA:HCl, HBr, HIhydrohalicacids (notHF).

3 One H+strongH2SO4sulfuricHNO3nitricHClO3, HClO4chloric, perchloric(X = Cl,Br,I,ClO3,ClO4,NO3)([HX] 0)Ka=[H3O+][X ][HX]= largeHX+ H2OH3O++ X stoichiometryStrong AcidsnotSA WAHC2H3O2acetic acidHNO2nitrous acidHFhydrofluoric acidlactic acidcitric acidH3 CCCOH OOHHHOCCH2 OCCH2 COOHCH2 OHCOOH stronger weakerKa=[H3O+][A ][HA]= 10 2to 10 12Ka=[H3O+][B][HB+]HB++ H2OB + H3O+CA of WB:Weak AcidsO2 + H2O 2 OH Na+(Li+, K+, Ca2+, etc) notA/BNa2O(aq)O2 + H2 ONaOH(aq) Na+(aq) + OH (aq)2 +Strong BasesOH O2 2 types SB:2 Na+(aq) + O2 (aq)ionicstoichiometryCH3NH2methylamine( CH3)2 NHdimethylamine (CH3)3 NtrimethylamineNH3, amines; related to NH3NH2(CH2)4NH2putracineAnthony UlinskipyridineadrenalineCCNCCCHHHHHCCCC CCHCHHHHOHCH2 NCH3 HHKb=[OH ][HB+][B]=10 2to 10 12Kb=[OH ][HA][A ]HA + OH A + H2 OCB of WA:Weak Bases36SA: HCl,HBr,HI,HClO3,HClO4,HNO3 Strong AcidsWeak Acidsif acid , but not SA WA:Strong Bases2 SB: ionic OH ,ionic O2 (=2OH )Weak BasesCA of WB(-ium)CB of WA (-ide, -ite, -ate)if base ,but not OH /O2 WB:H-something-NH2,-NH,-N-2.

4 Write acid -basereaction:AH3O+or B OH ,SB,WA,WBCB of SA,CB of WA,CA of one of 7categories:pH of X(aq) (WA) or Kb(WB)pH CalculationsWBWA,6. M (CH2OH)3 CNH2tris(hydroxymethyl)aminomethane3. M NaC7H5O2sodium benzoate1. M HCl2. M HC8H7O3mandelic acid4. M M CaO7. M NH3OH+Cl hydroxylammonium chloridepH Calculations, Examples5. M NaClKa1> Ka2H2A + H2O HA + H3O+Ka1HA + H2O A2 + H3O+Ka2H+donated stepwise:H2A, diprotic AcidsKb1> Kb2HA + H2O H2A + OH Kb2A2 + H2O HA + OH Kb1Ka1Kb2= KwKa2Kb1= KwDissociation Constants for Acids at 25 (or Ka1) x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 11 ChloroaceticHC2H2O2Cl x 10 x 10 x 10 x 10 x 10 x 10 4 Dichloroacetic x 10 x 10 x 10 x 10 10 Hydrofluoric x 10 4 Hydrosulfuric x 10 x 10 13 Hypobromous x 10 9 Hypochlorous x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 13 Dissociation Constants for Bases at 25 x 10 x 10 10 Dimethylamine(CH3) x 10 x 10 x 10 x 10 x 10 x 10 9 Trimethylamine (CH3) x 10 5 Tris(HOCH2) x 10 6 NameFormulaKa (or Ka1) x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 x 10 1