分析化學參考答案(武大第四版)

1、第一章 定量分析化學概論1. 某礦石的最大顆粒直徑為10mm，若其k值為0.1kgmm-2，問至少應采取多少試樣才具有代表性?若將該試樣破碎，縮分后全部通過10號篩，應縮分幾次?若要求最后獲得的分析試樣不超過100 g，應使試樣通過幾號篩?解：(1) 根據(jù)經(jīng)驗公式mqkd2，故至少采取試樣mq=0.1102=10kg(2) 要通過10號篩，d=2mm，應保留試樣mq0.122=0.4kg將10kg的試樣進行縮分：10()4 =0.625kg0.4kg可見需縮分4次方可滿足要求 。 查表1-1，故應通過20號篩。2.用氧化還原滴定法測得feso47h2o中鐵的質量分數(shù)為20.01%，20.03%

2、，20.04%，20.05%。計算：a.平均值；b.中位數(shù)；c.單次測量值的平均偏差；d.相對平均偏差；e.極差：f.相對極差。解：3.用沉淀滴定法測定純nacl中氯的質量分數(shù)，得到下列結果：59.82%，60.06%，60.46%，59.86%，60.24%。計算：a.平均結果；b.平均結果的絕對誤差；c.相對誤差；d.中位數(shù)；e.平均偏差；f.相對平均偏差。解：5.某試樣中含mgo約30%，用重量法測定時，fe3+產(chǎn)生共沉淀，設試液中的fe3+有1%進入沉淀。若要求測定結果的相對誤差小于0.1%，求試樣中fe2o3允許的最高質量分數(shù)為多少?解： 設試樣fe2o3中允許的最高質量分數(shù)為x%

3、6.某含cl-試樣中含有0.10%br-，用agno3進行滴定時，br-與cl-同時被滴定，若全部以cl-計算，則結果為20.0%。求稱取的試樣為下列質量時，cl-分析結果的絕對誤差及相對誤差。：a.0.1000 g;b.0.500 0 g;c.1.000 0 g。解： 7. 某試樣中含有約5%的s，將s氧化為so,然后沉淀為baso4。若要求在一臺靈敏度為0.1mg的天平上稱量baso4的質量時可疑值不超過0.1%，問必須稱取試樣多少克?解：8.用標記為0.100 0 moll-1hcl標準溶液標定naoh溶液，求得其濃度為0.101 8 mol.l-1，已知hcl溶液的真實濃度為0.099

4、 9moll-1，標定過程中其他誤差均較小，可以不計，求naoh溶液的真實濃度。10. 有0.098 2 moll-1的h2so4溶液480ml，現(xiàn)欲使其濃度增至0.100 0moll-1。問應加入0.500 0 moll-1的h2so4溶液多少毫升?13. 欲配制na2c2o4溶液用于在酸性介質中標定0.02 moll-1的kmno4溶液，若要使標定時，兩種溶液消耗的體積相近。問應配制多大濃度的na2c2o4溶液?配制100ml這種溶液應稱取na2c2o4多少克?(2)配制100ml這種溶液稱取 m na2c2o40.050.1126.077g14. 含s有機試樣0.471 g，在氧氣中燃燒

5、，使s氧化為so2，用預中和過的h2o2將so2吸收。全部轉化為h2so4，以0.108moll-1koh標準溶液滴定至化學計量點，消耗28.2ml。求試樣中s的質量分數(shù)。15. 將50.00ml 0.100 0moll-1ca(no3)2溶液加入到1.000 g含naf的試樣溶液中，過濾、洗滌。濾液及洗液中剩余的ca2+用0.050 0 moll-1edta滴定，消耗24.20ml。計算試樣中naf的質量分數(shù)。18. 不純sb2s3 0.251 3 g，將其在氧氣流中灼燒，產(chǎn)生的so2通入fecl3溶液中，使fe3+還原至fe2+，然后用0.020 00moll-1 kmno4標準溶液滴定f

6、e2+，消耗kmno4溶液31.80ml。計算試樣中sb2s3的質量分數(shù)，若以sb計，質量分數(shù)又為多少?19. 已知在酸性溶液中，fe2+與kmno4反應時，1.00mlkmno4溶液相當于0.111 7g fe，而1.00ml khc2o4h2c2o4 溶液在酸性介質中恰好與0.20ml上述kmno4溶液完全反應。問需要多少毫升0.200 0moll-1naoh溶液才能與上述1.00mlkhc2o4h2c2o4 溶液完全中和?(根據(jù)武漢大學第四版教材各章習題內(nèi)容撰寫,僅供參考)(根據(jù)武漢大學第四版教材各章習題內(nèi)容撰寫,僅供參考)第五章 重量分析和沉淀滴定法(根據(jù)武漢大學第四版教材各章習題內(nèi)容

7、撰寫,僅供參考)(根據(jù)武漢大學第四版教材各章習題內(nèi)容撰寫,僅供參考)(根據(jù)武漢大學第四版教材各章習題內(nèi)容撰寫,僅供參考) acknowledgements my deepest gratitude goes first and foremost to professor aaa , my supervisor, for her constant encouragement and guidance. she has walked me through all the stages of the writing of this thesis. without her consistent and

8、 illuminating instruction, this thesis could not havereached its present form. second, i would like to express my heartfelt gratitude to professor aaa, who led me into the world of translation. i am also greatly indebted to the professors and teachers at the department of english: professor dddd, pr

9、ofessor ssss, who have instructed and helped me a lot in the past two years. last my thanks would go to my beloved family for their loving considerations and great confidence in me all through these years. i also owe my sincere gratitude to my friends and my fellow classmates who gave me their help

10、and time in listening to me and helping me work out my problems during the difficult course of the thesis. my deepest gratitude goes first and foremost to professor aaa , my supervisor, for her constant encouragement and guidance. she has walked me through all the stages of the writing of this thesi

11、s. without her consistent and illuminating instruction, this thesis could not havereached its present form. second, i would like to express my heartfelt gratitude to professor aaa, who led me into the world of translation. i am also greatly indebted to the professors and teachers at the department of english: professor dddd, professor ssss, who have instructed and helped me a lot in the past two years. last my thanks would go to my beloved family for their loving considerations and great confidence in me all through these years. i also owe my