现代基础化学第9章酸碱和离子平衡6

1、波波 义义 耳耳碱碱 阿仑尼乌斯阿仑尼乌斯阿仑尼阿仑尼乌斯乌斯碱碱OH- -OH- -布朗斯特布朗斯特布朗斯特布朗斯特和和剑桥大学的剑桥大学的劳莱劳莱同时同时碱碱H3O+H+碱碱Ac- -Ac- -NH3NH3H2PO4- -H2PO4- -HPO42- -HPO42- -H2OH2OOH- -OH- -碱碱(2) 碱碱(1) H2OAc- -NH3Cl- -H2O OH- - NH3OH- -1. 弱酸与弱碱的解离平衡常数弱酸与弱碱的解离平衡常数H2OAc- -HAcAcOH3oa KNH3 OH- -NHOHNH3ob 4KOHOH3ow KowK14100 . 1 owKH2O- -SH

2、HSOH23oa1 K- -H2O- -HSSOH3oa2 2KH2OAc- - 2. 共轭酸碱的共轭酸碱的 之间的换算之间的换算oboaKK ，Ac- - OH- -oaKobKH2O OH- - oboaowKKK H2O- - - - H2O- - oa1Koa2K- - - - OH- - - OH- -ob1Kob2Kob2oa1owKKK ob1oa2owKKK owKowoaKcK20 owobKcK20 H2OAc- -xcxK 2HAcAcOH3oa242oaoaoacKKKx 解出：解出：）（条条件件：owoaKcK20 ,500 oaKc如如：oaHcKx cxxcxK2

3、2 oaOHH3OOHoaKobKobOHcK 242obobobOHcKKK %100 弱酸的初始浓度弱酸的初始浓度平衡时解离的弱酸浓度平衡时解离的弱酸浓度H2OAc- -xcxK 2oacx cxc cKoa 解：解：51075. 1 oHAca,K500,20 oaowoaKcKcK且且621011. 724 oaoaoaHcKKK15. 5 lgHpH51032. 1 oaHcK88. 4 pH解：解：51075. 1 oHAca,K88. 2 lgHpH500,20 oaowoaKcKcK且且31032. 1 oaHcK31031. 1 H解：解：owoboaHKKK ,1077.

4、14 oHCOOHa,K51074. 1 oNHb,3K111065. 5 oHCOOHa,owoHCOOb,KKK101075. 5 oNHb,owoNHa,34KKK1-7Lmol103.19H 解：解：H2O- - - - H2O- - 71007. 1 oa1K131026. 1 oa2K500,20 oa1owoa1KcKcK且且1oa1LmolH 41003. 1cK99. 3 pHSHSSOH3oa2 22K1Lmol101.26S 132解：解：-1L0.1molHClH H2O- - 71007. 1 oa1K- - H2O- - 131026. 1 oa2KH2O- - 2

5、01035. 1 oa2oa12223oaSHSOHKKK续解：续解：MOHSHS232oa219201035. 101. 01035. 11 . 0 KH2OAc- -解：解：51074. 1 obK1obLmolOH 351032. 11074. 110. 0cK88. 2 pOH12.11 pHH2O + +51074. 11 . 0)2 . 0( xxxKNHOHNH34ob1 . 01 . 0; 2 . 02 . 0 xx近近似似认认为为：51074. 12 x1Lmol 6107 . 8x06. 5 pOH94. 8 pHH2O1 oapKpH缓冲溶液演示实验缓冲溶液演示实验H2O

6、Ac- -解：解：1LmolAc 10. 0505020. 0501LmolHAc 10. 0505020. 050HAcAcOH3oa K51075. 1 oa3OHK76. 4 pHHClAc 1Lmol088. 02505050. 0220. 050Ac1LmolHAc 108. 02505050. 0220. 050HAcAcOH3oa K51014. 2088. 0108. 0 oa3OHK续续 解：解：67. 4 pHAc Ac 1LmolAc 108. 02505050. 0220. 0501LmolHAc 088. 02505050. 0220. 050HAcAcOH3oa K

7、51043. 1108. 0088. 0 oa3OHK续续 解：解：85. 4 pHCH3COOH + OH H2O + CH3COO H2O + CH3COOH H3O+ + CH3COO H3O+CH3COO CH3COOHCH3COO CH3COOHOH CH3COO CH3COOHHAc NaAc 缓冲体系中加入缓冲体系中加入HCl、NaOH 后组分浓度变化后组分浓度变化HA+H2O A- -+H3O+HAAOH3oa KAHAOHoa3-K 碱碱酸酸cclgpKpHoa 酸酸碱碱cclgpKpOHob 酸酸碱碱cclgpKpHob 141oapK13831017. 4,1031. 6

8、,1008. 7 oa3oa2oa1KKK解：解：9061002001031682.lg).lg(HPOPOHlgpKlgpKpH442oa2oa2 碱碱酸酸cc,oa2K解：解：酸根据：ccK碱碱lgp14pHobNH.lg10lg1.74. 95-41001481Lmol.NH02804解解得得：解：解：HAc+NaOH NaAc+H2O510751 .oHAc a,K已知：已知：910751.owoHAc a,oKKK此此反反应应的的续解：续解：;.).(.HAc03300100200100201000330010020010100.Ac76. 40)1075. 1lg(lgppH5oa

9、碱碱酸酸ccK1oaowobLmol.OH610353KKccK1Lmol.Ac0500020020020100完完全全反反应应后后的的738.pH 1Lmol.).(.OH02000500200301003012.pH 0.00 20.00 2.88 18.00 2.00 5.71 19.98 0.02 7.75 20.00 0.00 8.80 20.02 0.02 9.70 22.00 2.00 11.70 40.00 20.00 12.50大自然的溶洞奇观大自然的溶洞奇观X 射线胃肠钡餐造影射线胃肠钡餐造影X 射线胃肠钡餐造影射线胃肠钡餐造影CaF2(s) Ca2+(aq) + 2F-

10、-(aq)osp2oFCaKK2为为该该反反应应的的标标准准平平衡衡常常数数ospK对任意一个难溶电解质的溶解平衡：对任意一个难溶电解质的溶解平衡：AmBn(s) mAn+(aq) + nBm- -(aq)nmmnKBAospAmBn(s) mAn+(aq) + nBm- -(aq)msnAnsmB)(osp)()(BAnmnmnmnmmnsnmnsmsK相同类型的难溶电解质相同类型的难溶电解质不同类型的难溶电解质不同类型的难溶电解质解：解：)(ospnmnmsnmK2AgCloAgClsp,sK1oAgClsp,AgClLmol.510341Ks3CrOAg12oCrOAgsp,424242

11、12:1, 2,CrOAgsKnm对1oCrOAgsp,CrOAgLmol.42425310564KsJospKospKJ ospKJ ospKJ AgCl 沉淀的生成沉淀的生成Ag2CrO4 沉淀的生成沉淀的生成131091 .oMn(OH) sp,2K已已知知：解：解：1oNHb,Lmol.OH3351032110741100cKosp2.).(.OHMnKJ732210741103211001. 判断沉淀是否完全的标准判断沉淀是否完全的标准2. 影响沉淀完全的因素影响沉淀完全的因素(1) 同离子效应同离子效应解：解：1oCrOAgsp,)CrOAg(Lmol.42425310564Ks1

12、22242oCrOAgsp,101.10.104CrOAg42sK16Lmol101.7s解解得得：(2) 酸度的影响酸度的影响3910792 .oFe(OH) sp,3K已已知知：解：解：ospKJ Fe3+(aq) + 3OH- -(aq) Fe(OH)3(s)979333oFe(OH)sp,10. 2OHFe3K13oFe(OH)sp,Lmol.FeOH31333931003310010792K13oFe(OH)sp,Lmol.FeOH31235393105361010792K979333oFe(OH)sp,10. 2OHFe3K仍然有：仍然有：(3) 盐效应盐效应(1) 生成水生成水F

13、e(OH)3(s) + 3H+ (aq) Fe3+ (aq) + 3H2O Fe(OH)3(s) Fe3+ (aq) + 3OH- - (aq) 3H+ (aq) + 3OH- - (aq) 3H2OoFe(OH)sp,3K3owKFe(OH)3(s) + 3H+ (aq) Fe3+ (aq) + 3H2O 331439310792100110792.).(.)(owoFe(OH)sp,o3KKKM(OH)n(s) + nH+ (aq) Mn+ (aq) + nH2O nKKK)(owospo(2) 生成弱酸生成弱酸910322 .oOCaC sp,42K已知：已知：解：解：CaC2O4(s)

14、 + 2H+ (aq) Ca2+ (aq) + H2C2O4 续解：续解：CaC2O4(s) Ca2+ (aq) + C2O42- - oOCaCsp,42KH+(aq) + C2O42- -(aq) HC2O4 - - (aq) H+(aq) + HC2O4- -(aq) H2C2O4 1)(oOCaCa2,42K1)(oOCaCa1,42KCaC2O4(s) + 2H+ (aq) Ca2+ (aq) + H2C2O4 4529210058103751037510322010010.HOCHCaoa2oa1oOCaCsp,24222o42KKKxK另解：另解：4529100581037510

15、37510322.OCHOCOCHCaHOCHCaoa2oa1oOCaCsp,-2422-242422224222o42KKKKCaC2O4(s) + 2H+ (aq) Ca2+ (aq) + H2C2O4 4210058010010.x252210011052.oSnS sp,oZnS sp,KK，已知：已知：ZnS(s) + 2H+(aq) Zn2+(aq) + H2S解：解：01901026110071105213722.SHSSHZnHSHZnoSHa2,oSHa1,oZnSsp,-22-222222o22KKKK252210011052.oSnS sp,oZnS sp,KK，已知：已知：SnS(s) + 2H+(aq) Sn2+(aq) + H2S续解：续解：613725104710261100711001.SHSSHSnHSHSnoSHa2,oSHa1,oSnSsp,-22-222222o22KKKK(3) 生成弱碱生成弱碱131091 .oMn(OH) sp,2K已已知知：解：解：Mn(OH)2(s) + 2NH4+(aq) Mn2+(aq) + 2NH3H2O4251322210276107411091.).(.)(OHNHOHOHNHMnNHOHNHMnoNHb,oMn(OH)sp,242232242232o32KKKCaSO4(s) + CO32-