77 实验七十七 化学平衡常数及分配系数的测定

77 实验七十七 化学平衡常数及分配系数的测定 第一部分:思考题 实验七十七 化学平衡常数及分配系数的测定 1. 简述测定反应KI+I=KI的平衡常数的基本原理。 23 2. 在KI+I=KI反应平衡常数测定实验中，所用的碘量瓶和锥形瓶哪些需要干燥,哪些不需要干23 燥,为什么, 3. 在KI+I=KI反应平衡常数测定实验中，配制1、2号溶液的目的何在, 23 4. 在KI+I=KI反应平衡常数测定实验中，滴定CCl层样品时，为什么要先加KI水溶液, 234 5. 在KI+I=KI反应平衡常数测定实验中，配制的1、2号溶液是否需要恒温,为什么, 23 6. 在KI+I=KI反应平衡常数测定实验中，1、2号溶液达平衡后能否拿到恒温槽外取样,为什么, 23 3-7. 在化学平衡常数及分配系数的测定实验中，如何通过平衡常数求得I 的解离焓。 8. 在化学平衡常数及分配系数的测定实验中，为什么应严格控制恒温,如何控制, 9. 在KI+I=KI反应平衡常数测定实验中，需要直接测得哪些实验数据,如何测得, 23 --10. 在KI+I=KI反应平衡常数测定实验中，如何求得反应达平衡时I、I、I的浓度, 232 3 在KI+I=KI反应平衡常数测定实验中，若吸CCl层样品时混进水层对结果有何影响, 11.234 12. 在化学平衡常数及分配系数的测定实验中，吸取CCl层样品为什么要用洗耳球使移液管尖鼓气4 情况下穿过水层, 装好溶液后的碘量瓶为什么要立即塞紧磨口塞, 13. 14. 在KI+I=KI反应平衡常数测定实验中，每隔10min震荡一次的目的何在，若震荡时间不够有何23 影响, 15. 在KI+I=KI反应平衡常数测定实验中，滴定过程中哪些要用微量管,哪些要用25mL滴定管,23 为什么, 16. 在化学平衡常数及分配系数的测定实验中，若温度控制误差超?1?，有何影响, 17. 在化学平衡常数及分配系数的测定实验中，在配置系统溶液时，是否需要精确量取，为什么, 18. 在化学平衡常数及分配系数的测定实验中，滴定各层碘的浓度的目的何在, 第二部分:参考 答案 八年级地理上册填图题岩土工程勘察试题省略号的作用及举例应急救援安全知识车间5s试题及答案 实验七十七 化学平衡常数及分配系数的测定 1. 简述测定反应KI+I=KI的平衡常数的基本原理。 23 --答:在恒温下，碘(I)溶在含有碘离子(I)的溶液中，大部分成为络离子(I),并存在下列23平衡: personal and collective learning on your own, combining learning reading and discussion, read, learn, and understanding of the original principles, focused learning around topics discussion, ongoing positive and negative type education. Members should close their own thoughts, work, real life, comparing reflection and further improve the pertinence and effectiveness of learning, continue to unlock the buttons, correct wrong, think of practical realization in mind, party rules discipline, firm and correct political orientation, develop discipline, and being a qualified member of the adherence to the Constitution Party rules and political discipline. Second, "to do" as the key, seriously, do try to do, to set an example. Two lies in the doing. To learn to do, and the unity of knowledge, qualified party member, is the focus of this study and education and essential point. A qualified party members not only to watch his Constitution Party rules and talk to learn how, through, dark and light, and also what does he end up doing, is not a unity. This study and education, is essential to enhance the party's political awareness, awareness of overall, core, par. In learning education in the, each members are to control "told political, and has faith, do political qualified; told rules, and has discipline, do implementation discipline qualified; told moral, and has conduct, do conduct qualified; told dedication, and has as, do play role qualified" "four told four has" this put ruler, often measure himself, view himself, transformation himself, with actual action reflected learn of effectiveness, and reflected belief faith of power. To firm to to Central par, to XI General Secretary par, to party of theory, and route, and approach par, to Central of the decision deployment par, strongly maintenance Central of authority, maintenance XI General Secretary this core, strongly obey Central of concentrated unified led, in thought, and political 其平衡常数表达式为: ,,,cc,,,III333K (2) ,,，a,,cc,,,,,IIIIII222 --式中:α，c，γ分别为活度，浓度和活度系数。由于在同一溶液中，离子强度相同(I与I电价相同)。3由德拜-休克尔公式: I2 (3) lg,,0.509Z,ii1，I 计算可知，活度系数 (4) ,,,,,II3 在水溶液中，I浓度很小 2 (5) ,,1I2 一定温度下，故得: ,cc,I3 (6) K,,Kaccc,I2I 为了测定平衡常数，应在不干扰动态平衡的条件下测定平衡组成。在本实验中，当达到上述平 衡时，若用硫代硫酸钠标准液来滴定溶液中的I浓度，则会随着I的消耗，平衡将向左端移动，使22--I继续分解，因而最终只能测得溶液中I和I的总量。 323 2-2-- I， 2 SO, 2 I， SO22346 --为了解决这个问题，可在上述溶液中加入四氯化碳(CCl)，然后充分震荡 (I和I不溶于CCl)，434 当温度一定时，上述化学平衡及I在四氯化碳层和水层的分配平衡同时建立，如图1所示。首先测2 出I在HO及CCl层中的分配系数K，待平衡后再测出I在CCl中的浓度，根据分配系数，可算224d24 -出I在KI水溶液中的浓度。再取上层水溶液分析，得到I和I的总量。 223 ，，c，c,c,c (7) ,,I水层I,II,2233水层平衡 -由于在溶液中I总量不变，固有: c,c,c (9) ,,,I,初始I,I,3平衡平衡 因此，将平衡后各物质的浓度代入式(7)就可求出此温度下的平衡常数K。 c old moral, and has conduct, do conduct qualified; told dedication, and has as, do play role qualified" "four told four has" td political, and has faith, do political qualified; told rules, and has discipline, do implementation discipline qualified; t"tol e the party's political awareness, awareness of overall, core, par. In learning education in the, each members are to controlthrough, dark and light, and also what does he end up doing, is not a unity. This study and education, is essential to enhanc how, and education and essential point. A qualified party members not only to watch his Constitution Party rules and talk to learn xample. Two lies in the doing. To learn to do, and the unity of knowledge, qualified party member, is the focus of this studyt an edherence to the Constitution Party rules and political discipline. Second, "to do" as the key, seriously, do try to do, to send, party rules discipline, firm and correct political orientation, develop discipline, and being a qualified member of the ain mi e the pertinence and effectiveness of learning, continue to unlock the buttons, correct wrong, think of practical realizationd negative type education. Members should close their own thoughts, work, real life, comparing reflection and further improve original principles, focused learning around topics discussion, ongoing positive anpersonal and collective learning on your own, combining learning reading and discussion, read, learn, and understanding of th2ry this core, strongly obey Central of concentrated unified led, in thought, and politicalach par, to Central of the decision deployment par, strongly maintenance Central of authority, maintenance XI General Secretaappro d reflected belief faith of power. To firm to to Central par, to XI General Secretary par, to party of theory, and route, andt ruler, often measure himself, view himself, transformation himself, with actual action reflected learn of effectiveness, anhis pu 2. 在KI+I=KI反应平衡常数测定实验中，所用的碘量瓶和锥形瓶哪些需要干燥,哪些不需要干23 燥,为什么, 答:配置2号液的碘量瓶需要干燥，配置1号液的碘量瓶和锥形瓶不需要干燥。因为2号液是 -c,c,c用来测定平衡浓度的，平衡时I的浓度是用公式求得，初始的KI浓度必,,,初始I,I,I,3平衡平衡 须准确已知，所以必须干燥。1号液是用来测I在HO及CCl层中的分配系数K，分配系数与浓224d度无关，锥形瓶是滴定用的，滴定的是I的总的物质的量，与浓度无关，因此不需干燥。 2 3. 在KI+I=KI反应平衡常数测定实验中，配制1、2号溶液的目的何在, 23 答:配置1号液是用来测I在HO及CCl层中的分配系数K，配置2号液是用来测定反应224d KI+I=KI达平衡时各物质的平衡浓度的。 23 4. 在KI+I=KI反应平衡常数测定实验中，滴定CCl层样品时，为什么要先加KI水溶液, 234 答:硫代硫酸钠标准液与溶液中I的反应是在水层中进行，滴定CCl层样品的I时，先加KI242水溶液是为了加快CCl层中的I借助于反应KI+I=KI提取到水层中，有利于NaSO滴定的顺利4223223进行。 5. 在KI+I=KI反应平衡常数测定实验中，配制的1、2号溶液是否需要恒温,为什么, 23 答:需要恒温，因为分配系数K和反应平衡常数均与温度有关，定温下为定值。 d 6. 在KI+I=KI反应平衡常数测定实验中，1、2号溶液达平衡后能否拿到恒温槽外取样,为什么, 23 答:不能，因为反应平衡常数与温度有关，温度改变，平衡会发生移动。 3-7. 在化学平衡常数及分配系数的测定实验中，如何通过平衡常数求得I 的解离焓。 - 答:测出两个反应温度下的的平衡常数，再由下式可计算的I解离焓。 3 KTRTT，，c112,,Hln rm，，,TTKT21c2 8. 在化学平衡常数及分配系数的测定实验中，为什么应严格控制恒温,如何控制, 答:因为分配系数K和反应平衡常数均与温度有关，定温下为定值。所以应严格控制恒温。所d y. This study and education, is essential to enhance the party's political awareness, awareness of overall, core, par. In leaa unitatch his Constitution Party rules and talk to learn how, through, dark and light, and also what does he end up doing, is not qualified party member, is the focus of this study and education and essential point. A qualified party members not only to wdge, to do" as the key, seriously, do try to do, to set an example. Two lies in the doing. To learn to do, and the unity of knowlediscipline, and being a qualified member of the adherence to the Constitution Party rules and political discipline. Second, " evelopons, correct wrong, think of practical realization in mind, party rules discipline, firm and correct political orientation, dreal life, comparing reflection and further improve the pertinence and effectiveness of learning, continue to unlock the buttwork, d learning around topics discussion, ongoing positive and negative type education. Members should close their own thoughts, ing on your own, combining learning reading and discussion, read, learn, and understanding of the original principles, focusepersonal and collective learn3, and politicalntral of authority, maintenance XI General Secretary this core, strongly obey Central of concentrated unified led, in thoughtce CeSecretary par, to party of theory, and route, and approach par, to Central of the decision deployment par, strongly maintenan actual action reflected learn of effectiveness, and reflected belief faith of power. To firm to to Central par, to XI Generalwith as, do play role qualified" "four told four has" this put ruler, often measure himself, view himself, transformation himself,cipline, do implementation discipline qualified; told moral, and has conduct, do conduct qualified; told dedication, and has as disrning education in the, each members are to control "told political, and has faith, do political qualified; told rules, and h 配置溶液放在恒温水浴中恒温。 9. 在KI+I=KI反应平衡常数测定实验中，需要直接测得哪些实验数据,如何测得, 23 答:配制的1、2号溶液达平衡后，用硫代硫酸钠标准液来滴定两溶液中的水层和四氯化碳层I2浓度所消耗的硫代硫酸钠标准液的体积。 用标准NaSO溶液滴定碘时，先要滴定至淡黄色再加淀粉溶液滴至水层淀粉指示剂的蓝色消223 失。取CCl层样品时勿使水层进入移液管中，为此用洗耳球使移液管尖鼓气情况下穿过水层插入4 CCl层中取样。在滴定CCl层样品的I时，应加入10ml0.1mol/L的KI水溶液以加快CCl层中的4424I借助于反应KI+I=KI提取到水层中，这样有利于NaSO滴定的顺利进行，滴定时要充分摇荡，223223 细心地滴至水层淀粉指示剂的蓝色消失，四氯化碳层不再现红色。滴定后的和末用完的CCl皆应倒4人回收瓶中。 --10. 在KI+I=KI反应平衡常数测定实验中，如何求得反应达平衡时I、I、I的浓度, 232 3 答:为了测定平衡常数，应在不干扰动态平衡的条件下测定平衡组成。在本实验中，当达到上述平衡时，若用硫代硫酸钠标准液来滴定溶液中的I浓度，则会随着I的消耗，平衡将向左端移动，22 --使I继续分解，因而最终只能测得溶液中I和I的总量。 323 2-2-- I， 2 SO, 2 I， SO22346 --为了解决这个问题，可在上述溶液中加入四氯化碳(CCl)，然后充分震荡 (I和I不溶于CCl)，434当温度一定时，上述化学平衡及I在四氯化碳层和水层的分配平衡同时建立，如图1所示。首先测2 出I在HO及CCl层中的分配系数K，待平衡后再测出I在CCl中的浓度，根据分配系数，可算224d24 -出I在KI水溶液中的浓度。再取上层水溶液分析，得到I和I的总量。 223 ，，c，c,c,c (7) ,,I水层I,II,2233水层平衡 -由于在溶液中I总量不变，固有: c,c,c (9) ,,,I,初始I,I,3平衡平衡 因此，将平衡后各物质的浓度代入式(6)就可求出此温度下的平衡常数K。 c ,cc,I3K,,K (6) accc,I2I 11. 在KI+I=KI反应平衡常数测定实验中，若吸CCl层样品时混进水层对结果有何影响, 234 d political, and has faith, do political qualified; told rules, and has discipline, do implementation discipline qualified; t"tol e the party's political awareness, awareness of overall, core, par. In learning education in the, each members are to controlthrough, dark and light, and also what does he end up doing, is not a unity. This study and education, is essential to enhanc how, and education and essential point. A qualified party members not only to watch his Constitution Party rules and talk to learn xample. Two lies in the doing. To learn to do, and the unity of knowledge, qualified party member, is the focus of this studyt an edherence to the Constitution Party rules and political discipline. Second, "to do" as the key, seriously, do try to do, to send, party rules discipline, firm and correct political orientation, develop discipline, and being a qualified member of the ain mi e the pertinence and effectiveness of learning, continue to unlock the buttons, correct wrong, think of practical realizationd negative type education. Members should close their own thoughts, work, real life, comparing reflection and further improve original principles, focused learning around topics discussion, ongoing positive anpersonal and collective learning on your own, combining learning reading and discussion, read, learn, and understanding of th4ry this core, strongly obey Central of concentrated unified led, in thought, and politicalach par, to Central of the decision deployment par, strongly maintenance Central of authority, maintenance XI General Secretaappro d reflected belief faith of power. To firm to to Central par, to XI General Secretary par, to party of theory, and route, andt ruler, often measure himself, view himself, transformation himself, with actual action reflected learn of effectiveness, anhis puold moral, and has conduct, do conduct qualified; told dedication, and has as, do play role qualified" "four told four has" t 答:吸CCl层样品时混进水层会造成CCl层碘的浓度有误差。 44 12. 在化学平衡常数及分配系数的测定实验中，吸取CCl层样品为什么要用洗耳球使移液管尖鼓气4 情况下穿过水层, 答:防止水层进入移液管中而引起实验误差。 13.装好溶液后的碘量瓶为什么要立即塞紧磨口塞, 答:因为碘和四氯化碳易挥发，故立即塞紧磨口塞是为了防止碘和CCl挥发。 4 14. 在KI+I=KI反应平衡常数测定实验中，每隔10min震荡一次的目的何在，若震荡时间不够有何23 影响, 答:每隔10min振荡一次是为了加快分配平衡的到达。若振荡时间不够，没有到达分配平衡，会导致实验结果有误差。 15. 在KI+I=KI反应平衡常数测定实验中，滴定过程中哪些要用微量管,哪些要用25mL滴定管,23 为什么, 答:滴定1号液25ml水层样品和2号液5mlCCl层时要用微量管，滴定1号液5mlCCl层和244号液25ml水层样品时用25ml滴定管。因为滴定1号液25ml水层样品和2号液5mlCCl层时所需硫4代硫酸钠体积少，用微量管可以减少滴定误差;而滴定1号液5mlCCl层和2号液25ml水层样品时4 硫代硫酸钠所用体积则较多，即要用容量大的滴定管。 16. 在化学平衡常数及分配系数的测定实验中，若温度控制误差超?1?，有何影响, 答:化学平衡常数及分配系数对温度的影响较为灵敏，若温度控制误差超?1?，会导致较大的实验误差。 17. 在化学平衡常数及分配系数的测定实验中，在配置系统溶液时，是否需要精确量取，为什么, 答:不需要精确量取。因为最终所需的各浓度都用硫代硫酸钠精确滴定出来，配置系统溶液的多少，不会影响化学平衡常数及分配系数。但至少应能保证实验分析用量。 18. 在化学平衡常数及分配系数的测定实验中，滴定各层碘的浓度的目的何在, as disrning education in the, each members are to control "told political, and has faith, do political qualified; told rules, and hy. This study and education, is essential to enhance the party's political awareness, awareness of overall, core, par. In leaa unitatch his Constitution Party rules and talk to learn how, through, dark and light, and also what does he end up doing, is not qualified party member, is the focus of this study and education and essential point. A qualified party members not only to wdge, to do" as the key, seriously, do try to do, to set an example. Two lies in the doing. To learn to do, and the unity of knowlediscipline, and being a qualified member of the adherence to the Constitution Party rules and political discipline. Second, " evelopons, correct wrong, think of practical realization in mind, party rules discipline, firm and correct political orientation, dreal life, comparing reflection and further improve the pertinence and effectiveness of learning, continue to unlock the buttwork, d learning around topics discussion, ongoing positive and negative type education. Members should close their own thoughts, ing on your own, combining learning reading and discussion, read, learn, and understanding of the original principles, focusepersonal and collective learn5, and politicalntral of authority, maintenance XI General Secretary this core, strongly obey Central of concentrated unified led, in thoughtce CeSecretary par, to party of theory, and route, and approach par, to Central of the decision deployment par, strongly maintenan actual action reflected learn of effectiveness, and reflected belief faith of power. To firm to to Central par, to XI Generalwith as, do play role qualified" "four told four has" this put ruler, often measure himself, view himself, transformation himself,cipline, do implementation discipline qualified; told moral, and has conduct, do conduct qualified; told dedication, and has 答:滴定1号液的25ml水层样品是为了求出水层中碘的浓度，滴定5mlCCl层是为了求出CCl44层中碘的浓度，由此来求出分配系数。滴定2号液的25ml水层样品是为了求出水层中碘的总浓度， --滴定5mlCCl层是为了求出CCl层中碘的浓度，从而求出化学反应达平衡时I、I、I的平衡浓度。 442 3 through, dark and light, and also what does he end up doing, is not a unity. This study and education, is essential to enhanc how, and education and essential point. A qualified party members not only to watch his Constitution Party rules and talk to learn xample. Two lies in the doing. To learn to do, and the unity of knowledge, qualified party member, is the focus of this studyt an edherence to the Constitution Party rules and political discipline. Second, "to do" as the key, seriously, do try to do, to send, party rules discipline, firm and correct political orientation, develop discipline, and being a qualified member of the ain mi e the pertinence and effectiveness of learning, continue to unlock the buttons, correct wrong, think of practical realizationd negative type education. Members should close their own thoughts, work, real life, comparing reflection and further improve original principles, focused learning around topics discussion, ongoing positive anpersonal and collective learning on your own, combining learning reading and discussion, read, learn, and understanding of th6ry this core, strongly obey Central of concentrated unified led, in thought, and politicalach par, to Central of the decision deployment par, strongly maintenance Central of authority, maintenance XI General Secretaappro d reflected belief faith of power. To firm to to Central par, to XI General Secretary par, to party of theory, and route, andt ruler, often measure himself, view himself, transformation himself, with actual action reflected learn of effectiveness, anhis puold moral, and has conduct, do conduct qualified; told dedication, and has as, do play role qualified" "four told four has" td political, and has faith, do political qualified; told rules, and has discipline, do implementation discipline qualified; t"tol e the party's political awareness, awareness of overall, core, par. In learning education in the, each members are to control