沉淀滴定法概要VIP免费

第八章重量分析法和沉淀滴定法1.已知2002424]][[][SOCaCaSO水，忽略离子强度的影响，计算CaSO4的固有溶解度，并计算饱和CaSO4溶液中，非离解形式的Ca2+的百分数。解：%6.37%100101.91082.11082.1%%100%100]Ca[%)2(Lmol1082.1101.9200200]][SOCa[]CaSO)[1(633sp00200136sp0sp0242004未解离形式未解离形式＝水KssssKsKsss2.已知某金属氢氧化物M(OH)2的Ksp=4×10-15，向0.10mol/LM2+溶液中加入NaOH，忽略体积变化和各种氢氧基络合物，计算下列不同情况生成沉淀时的pH值：(1)M2+离子有1%沉淀；(2)M2+离子有50%沉淀；(3)M2+离子有99%沉淀。解：30.81000.2%)991(10.0104][])[3(45.71083.2%)501(10.0104][])[2(30.71001.2%)11(10.0104][])[1()1(10.0104][][104]][[6152715271521521522pHMKOHpHMKOHpHMKOHxMKOHKOHMspspspspsp3.考虑盐效应，计算下列微溶化合物的溶解度：（1）BaSO4在0.10mol/LNaCl溶液中；（2）BaSO4在0.10mol/LBaCl2溶液中。解：1510SOBa02242SO2SOBa2Ba22Lmol109.23486.03746.0101.1]][SOBa[3486.010.040000328.0110.02512.0lg3746.010.050000328.0110.02512.0lg10.0)110.0110.0(21)I1(242242422sKKsspsp1810SOBa0spsp242242SO2SOBa2Ba22Lmol109.12225.02565.010.0101.110.0]][SO[Ba]SO[,10.010.0]Ba[2225.030.040000328.0130.02512.0lg2565.030.050000328.0130.02512.0lg30.0)120.0210.0(21I)2(242242422sKKsss4.考虑酸效应，计算下列微溶化合物的溶解度：（1）CaF2在pH=2.0的溶液中；（2）BaSO4在2.0mol/L的HCl中；（3）PbSO4在0.10mol/LHNO3中；（4）CuS在pH=0.5的饱和H2S中（[H2S]≈0.1mol/L）解：13322441132aasp2aa2-2spaaFF-Lmol102.110106.6106.64107.2)][(4)2][(]][F[Ca2][][F)1HKKKssHKKsKsHKKc142102sp2242sp22-24Lmol105.1101.1200201200]][SOBa[2000.21010][SO)2KssKss1428122-24Lmol102.4106.11111101010][SO)3sss1152236362222sp2225.05.07157157-22-2Lmol105.6102.9106106102.9]][S[Cu102.91010103.1101.7103.1101.7103.11.0][S]H[]H[)1.0(][S)412121ssKKKKKKsaaaaa5.计算BaSO4在0.010mol/LBaCl2-0.070mol/LHCl中的溶解度。解：17101022242SOBa2222Lmol107.63486.03746.0010.0101.183486.03746.0101.18010.08070.01010]SO[010.0010.0]Ba[3486.03746.0)1(31.0)1070.01070.01020.02010.0(21I242ssKssssp，＝可知：由题6.考虑S2-的水解，计算下列硫化物在水中的溶解度。1）CuS2)MnS解：11427.4-363627.4-22sp7.4-71577-27157S2Lmol1023.11010610610]][S[Cu10103.1101.7103.11010101.7103.1]S)[1(2ssKsss143151410awMnSsp,-2---22--23--22Lmol106.6101.7101021]][H[S][HS]][H[OH]][S[Mn]][OH][HS[MnOHHSMnOHMnSMnS)2(S)22(HsKKKs则的水解反应考虑到7.将固体AgBr和AgCl加入50.0ml纯水中，不断搅拌使其达到平衡。计算溶液中Ag+的浓度。解：设AgBr的溶解度为s1，AgCl的溶解度为s2，则155852811021213211Lmol1034.11034.11072.3]Ag[1034.1,1072.3108.1)(]][Cl[Ag100.5)(]][BrAg[ssssssss可以求得8.计算CaC2O4在下列溶液中的溶解度：（1）pH=4.0的HCl溶液中；（2）pH=3.0含有草酸总浓度为0.010mol/L的溶液中。解：1623.39-242sp23.323.1-242223.1252353OC1541.09OCsp41.02524542OCLmol104.310100.2]OC[1010010.0]OC[][Ca10109.5104.610104.6101)2Lmol102.710100.210109.5104.610104.6101][H][H1)1(-242-242122-242KsssKsKKKaaa同离子效应酸效应酸效应9.计算CaCO3在纯水中的溶解度和平衡时溶液中的pH值。解：90.9lg14OH14HLmol100.8106.510109.2]][H[CO][HCO]][H[OH]][CO[Ca]][OH][HCO[CaOHHCOCaOHCaCO的水解反应CaCO到15311149)(aw)sp(CaCO-23-3--232--323--322333223sppsKKKsCOH则考虑10.为了防止AgCl从含有0.010mol/LAgNO3和0.010mol/LNaCl溶液中析出沉淀，应加入氨的总浓度是多少（忽略溶液体积变化）？解：1NH105.774.505.7224.324.3374.52305.7324.3)Ag(NH74.510)Ag(NH)Ag(NHAgspLmol24.0010.0222.0Lmol22.0102101041010]NH[10]NH[10]NH[10110108.1010.0010.0][Cl]][Cl[Ag3333ccK11.计算AgI在0.010mol/LNaS2O3和0.010mol/LKI溶液中的溶解度。解：151748.948....