Acid–Base-Titration---Zagazig-University：–碱滴定酸-扎加齐课件

21、没有人陪你走一辈子，所以你要适应孤独，没有人会帮你一辈子，所以你要奋斗一生。22、当眼泪流尽的时候，留下的应该是坚强。23、要改变命运，首先改变自己。24、勇气很有理由被当作人类德性之首，因为这种德性保证了所有其余的德性。-温斯顿丘吉尔。25、梯子的梯阶从来不是用来搁脚的，它只是让人们的脚放上一段时间，以便让别一只脚能够再往上登。AcidBase Titration-Zagazig University：碱滴定酸-扎加齐克大学Acid/Base Titration Acid/Base Titration Dr.Hisham Ezzat AbdellatefDr.Hisham Ezzat AbdellatefProf.of Analytical Chemistry Prof.of Analytical Chemistry Clinical Pharmacy Code:105 Electrolyte and the theory of electrolytic DissociationElectrolytesconduct the electric currentmineral acid,caustic alkalies and saltsnonelectrolytesnonconducting solutionscane sugar,glycerin and ethyl acetate.AcidBase Titration Pure water is a bad conductor of electricityacid as HCl H+Cl-base as KOH K+OH-salt as Na2SO4 Na+SO42-Molecule Dissociation ions Dissolved in waterStrong and weak electrolytesNaCl Na+ClK2SO4 2K+SO42Na2HPO4 2Na+H+PO43 Arrhenius therefore introduced a quantity a,called the degree of dissociation“a“=1 strong electrolyte“a”very far from unity.=weak electrolyte Law of mass action The rate of a chemical reaction is proportional to the active masses of the reacting substances.diluted solution concentrationLaw of mass action Vf =A.B.KfVb =C.D.KbKf A.B=Kb C.Dequilibrium constantequilibrium constant The dissociation of waterH2O H+OH H+.OH =Kw.(2)The ionic product of waterThe dissociation of water25oC;the value of Kw H+.OH =1014H+2 =Kw =1 x 1014(3)Hydrogen ion exponent(pH):H+106,105 1 x 107 108,109 Acid base Neutral Procedure for TitrationpH is defined as equal to the logarithm of the hydrogen ion concentration with a negative sign.pH=log H+The pH scale1 2 3 4 5 6 7 8 9 10 11 12 13 14acidacid neutral neutral basebase Stomach juice:pH=1.0 3.0Human blood:pH=7.3 7.5Lemon juice:pH=2.2 2.4Seawater:pH=7.8 8.3Vinegar:pH=2.4 3.4Ammonia:pH=10.5 11.5Carbonated drinks:pH=2.0 4.0 0.1M Na2CO3:pH=11.7Orange juice:pH=3.0 4.01.0M NaOH:pH=14.0Figure:The pH scale and pH values of some common substancesFigure:A pH meterFigure:Indicator paper being used to measure the pH of a solutionppKw =pH +pOH pH =pKw pOHor pH =14 pOHor pOH=14 pHAcids and bases:Arrhenius theoryAcid H+when dissolved in waterBases,OH Acid and basepH calculations1.Solution of strong acids and strong basesH+or OH =concentrationExample 1 Calculate the pH value of a solution of a completely ionised 1.0 N solution of acid;or base.?Solution:H+=1M pH=log 1=0 (zero)similarly,in a completely ionised 1.0 N solution of base OH=1 M pOH=log 1=0(zero)Example 2Calculate the H+and pH of 0.009 N hydrochloric acid?solution H+=0.009 NpH =log(9.0 X 103)=log 9.0 log 103pH =0.95+3.00=2.05Example 3 Calculate the pH values of a solution of sodium hydroxide whose OH is 1.05 x 103?solutionpOH =(log 1.05+log 103)pOH =(0.02 3)=2.98pH =14 2.98 =11.02Example 4Calculate the hydrogen ion concentration of a solution of pH 5.3?solutionpH =log H+5.3=log H+H+=5.01 x 106 MExample 5Calculate the hydroxyl ion concentration of a solution of pH 10.75?solutionpOH=14 10.75=3.25OH =the antilog of 3.25OH =5.62 x 104 MpH calculations2.Solution of weak acids and bases A)Calculation of pH of solution of weak acids pH =(pKa +pCa)B)Calculation of pH of solution of weak bases:pH=pKw (pKb+pCb)pH of saltsA)Salts of strong acids or bases KCl K+Cl-K+OH-KOHCl-+H+HClThe equilibrium between the hydrogen and hydroxyl ions in water H2O H+OHB)Salts of weak acids or bases(hydrolysis)Salts of weak acids(or bases)react with water to give basic(or acidic)solutionsHydrolysis reverse of neutralizationi)Salts of weak acids and strong bases:H2O+CH3COO CH3COOH +OHpH =(pKw pCa +pKa)ii)Salts of weak bases and strong acids:NH4+H2O NH4OH +H+pH=(pKw+pCs pKb)iii)Salts of weak acids and weak bases:pH=pKw+pKa pKbBuffer solutions Resist changes in pH caused by addition of small amounts of acid or base;or upon dilution.Types of buffers谢谢你的阅读v知识就是财富v丰富你的人生56、书不仅是生活，而且是现在、过去和未来文化生活的源泉。库法耶夫57、生命不可能有两次，但许多人连一次也不善于度过。吕凯特58、问渠哪得清如许，为有源头活水来。朱熹59、我的努力求学没有得到别的好处，只不过是愈来愈发觉自己的无知。笛卡儿60、生活的道路一旦选定，就要勇敢地走到底，决不回头。左拉