一、常見重點(diǎn)問題答疑I.AnswerstoFrequentlyAskedKeyQuestions1.什么是凈化置換沉淀法？請用硫酸鋅溶液凈化的例子，說明其反應(yīng)原理。1.Whatisthepurificationdisplacementprecipitationmethod?Pleaseusetheexampleofzincsulfatesolutionpurificationtoillustrateitsreactionprinciple.解答：Answer:（1）定義：凈化置換沉淀法是利用金屬電性差異（較“活潑”的金屬和較“不活潑”的金屬離子），讓較活潑的金屬把較不活潑的金屬離子從溶液中“換”出來，形成沉淀，從而分離雜質(zhì)或提取金屬的方法。(1)Definition:Purificationdisplacementprecipitationmethodisamethodthatmakesuseofthedifferenceinelectricalpropertiesofmetals(more"active"metalsandless"inactive"metalions)toallowmoreactivemetalsto"exchange"lessinactivemetalionsfromthesolutiontoformprecipitates,therebyseparatingimpuritiesorextractingmetals.（2）例子：在硫酸鋅溶液凈化中，鋅粉（較活潑）能置換出溶液中的銅離子（Cu2?）和鎘離子（Cd2?），因?yàn)殇\比銅、鎘更“活潑”。反應(yīng)后，銅、鎘變成固體沉淀，鋅粉變成鋅離子進(jìn)入溶液，既除去了雜質(zhì)，又不影響溶液中的鋅。(2)Example:Inthepurificationofzincsulfatesolution,zincpowder(moreactive)candisplacecopperions(Cu2?)andcadmiumions(Cd2?)inthesolution,becausezincismore"active"thancopperandcadmium.Afterthereaction,copperandcadmiumbecomesolidprecipitates,andzincpowderbecomeszincionsandentersthesolution,whichnotonlyremovesimpurities,butalsodoesnotaffectthezincinthesolution.2.在工廠用鋅粉置換硫酸鋅溶液中的銅雜質(zhì)時(shí)，哪些操作能加快反應(yīng)速度？請舉3個(gè)實(shí)際操作中的例子。2.Whatoperationscanspeedupthereactionspeedwhenzincpowderisusedtodisplacecopperimpuritiesinzincsulfatesolutioninthefactory?Pleasegiveme3examplesinactualoperation.解答：Answer:（1）用粉末狀鋅粉：鋅粉顆粒越細(xì)，與溶液接觸的面積越大，反應(yīng)越快（比表面積影響）。(1)Usepowderedzincpowder:Thefinerthezincpowderparticles,thelargerthecontactareawiththesolution,andthefasterthereaction(influenceofspecificsurfacearea).（2）加熱溶液：適當(dāng)提高溫度（如控制在60-80℃），能加快反應(yīng)（溫度影響）。(2)Heatthesolution:Appropriatelyincreasingthetemperature(suchascontrollingitat60-80°C)canspeedupthereaction(temperatureinfluence).（3）加強(qiáng)攪拌：攪拌能讓鋅粉和溶液混合更均勻，露出鋅粉新鮮表面，反應(yīng)更迅速（攪拌影響）。(3)Strengthenstirring:Stirringcanmixthezincpowderandsolutionmoreevenly,exposethefreshsurfaceofzincpowder,andreactmorequickly(stirringinfluence).3.為什么在硫酸鋅溶液凈化中，常用鋅粉除去溶液中的Cu2?、Cd2?等雜質(zhì)？這樣做有什么好處？3.WhyiszincpowdercommonlyusedtoremoveimpuritiessuchasCu2?andCd2?inthepurificationofzincsulfatesolution?Whatarethebenefitsofdoingso?解答：Answer:（1）原因：鋅的“電性”比銅、鎘更活潑（鋅比銅、鎘易失去電子），能把Cu2?、Cd2?從溶液中“置換”出來，形成固體沉淀。(1)Reason:The"electricity"ofzincismoreactivethanthatofcopperandcadmium(zincloseselectronsmoreeasilythancopperandcadmium),anditcan"displace"Cu2?andCd2?fromthesolutiontoformasolidprecipitate.（2）好處：除去銅、鎘等雜質(zhì)后，硫酸鋅溶液更純凈，能避免這些雜質(zhì)影響后續(xù)鋅電解的效率（如降低電流效率）和陰極鋅的質(zhì)量（如導(dǎo)致鋅不純、剝鋅困難）。(2)Benefits:Afterremovingimpuritiessuchascopperandcadmium,thezincsulfatesolutionispurer,whichcanpreventtheseimpuritiesfromaffectingtheefficiencyofsubsequentzincelectrolysis(suchasreducingcurrentefficiency)andthequalityofcathodezinc(suchascausingimpurezincanddifficultyinstrippingzinc).二、常見難點(diǎn)問題答疑II.AnswerstoFrequentlyAskedDifficultQuestions1.在實(shí)際操作中，為什么既要控制鋅粉用量（過量），又要保證充分?jǐn)嚢瑁窟@兩個(gè)操作配合有什么作用？1.Whyshouldwenotonlycontrolthedosage(excessive)ofzincpowder,butalsoensuresufficientstirringinactualoperation?Whatisthefunctionofthesetwooperationsincombination?解答：鋅粉過量是為了“換干凈”溶液中的雜質(zhì)（比如銅離子），確保雜質(zhì)完全沉淀；充分?jǐn)嚢枋菫榱俗屵^量的鋅粉和溶液充分接觸，避免鋅粉沉在底部“不干活”。兩者配合能保證反應(yīng)更徹底、更快，提高凈化效率，減少雜質(zhì)殘留。Answer:Excessivezincpowderisto"clean"theimpurities(suchascopperions)inthesolutiontoensurethattheimpuritiesarecompletelyprecipitated;thepurposeofthoroughstirringistomaketheexcesszincpowderfullycontactwiththesolution,preventingthezincpowderfromsinkingtothebottomand"notworking".Thecombinationofthetwocanensurethatthereactionismorethoroughandfaster,improvethepurificationefficiencyandreduceimpurityresidues.2.為什么能用鐵置換出硫酸銅溶液中的銅，卻不能用銅置換出硫酸亞鐵溶液中的鐵？請用金屬“活潑性”解釋。2.Whycanironbeusedtodisplacecopperincoppersulfatesolution,butcoppercannotbeusedtodisplaceironinferroussulfatesolution?Pleaseexplainusingthe"activity"ofmetals.解答：因?yàn)殍F比銅“活潑”（鐵的電性更負(fù)），所以鐵能把銅離子從溶液中置換出來（如Fe+CuSO?=Cu↓+FeSO?）。而銅不如鐵“活潑”，無法把鐵離子從溶液中置換出來，所以銅和硫酸亞鐵溶液不反應(yīng)。Answer:Becauseironismore"active"thancopper(ironismoreelectricallynegative),ironcandisplacecopperionsfromthesolution(suchasFe+CuSO?=Cu↓+FeSO?).Copperisnotas"active"asironandcannotdisplaceironionsfromthesolution,socopperandferroussulfatesolutiondonotreact.3.如果硫酸鋅溶液中銅離子濃度特別高，在置換時(shí)需要調(diào)整哪些工藝參數(shù)？為什么？3.Whatprocessparametersneedtobeadjustedduringdisplacementiftheconcentrationofcopperionsinthezincsulfatesolutionisparticularlyhigh?Why?解答：Answer:（1）需要調(diào)整的參數(shù)：①增加鋅粉用量（比正常情況多加一些）；②適當(dāng)提高攪拌速度；③可能需要延長反應(yīng)時(shí)間。(1)Parameterstobeadjusted:①Increasethedosageofzincpowder(morethannormal);②Increasethestirringspeedappropriately;③Itmaybenecessarytoextendthereactiontime.（2）原因：銅離子濃度高時(shí)，需要更多鋅粉才能把雜質(zhì)“換”干凈；加快攪拌能讓鋅粉和高濃度的銅離子充分接觸；延長時(shí)間能確保反應(yīng)完全，避免雜質(zhì)殘留。(2)Reason:Whentheconcent