电解浓氯化铜溶液出现“黑色”现象的探究

对电解浓氯化铜溶液时,阴极出现"黑色"现象的原因做了初步的探究,得出其"黑色"并非是由微小铜粒产生的,而是生成的亚铜离子与溶液中的铜离子和氯离子形成的络离子所致.     

电解KI溶液的微型实验

电解、电镀、电池和电腐蚀是大学无机化学或普通化学实验的必备实验内容。许多学校的电解实验多取材于电解水、电解食盐水或电解氯化铜溶液等,我校是用串联两对Zn—Cu原电池为电源,电解KI溶液为普化实验内容。作者将常规型实验作了微型化改革,实验在2ml的微型试管中进行,取得良好的效果。具有现象明显,节约试剂,操作简便,富有思考     

用石墨作电极电解氯化铜溶液现象的探讨

通过实验探究了电解CuCl2溶液阴极析出物质的位置和析出物质的成分,对演示实验中出现的"异常"现象作出了合理解释。     

实验探究电解重铬酸钾溶液

通过实验探究在不同电压、pH、浓度、电极材料等条件下电解重铬酸钾溶液,并从理论上解释现象各异的原因,得到“重铬酸根离子可以在阴极放电”“用石墨电极也可以电解处理含重铬酸根离子的废水”等结论。     

对"电解质溶液导电性演示实验"的改进

人民教育出版社出版的高中化学教材 ,从 1 980年到现在 ,虽经多次变动 ,但在讲强弱电解质时 ,都采用几乎同一个实验 (个别文字略有不同 )。 2 0 0 1年版实验教材中是这样表述的 :按图 1所示的装置把仪器连接好 ,然后把相同条件下的HCl、CH3 COOH、NaOH、NaCl溶液和氨水分别倒入 5个烧杯中 ,接通电源 ,观察灯泡发光的明亮程度。图 1实验结果表明 ,连接插入CH3 COOH溶液和氨水的电极上的灯泡比其他 3个灯泡暗。该实验存在以下 4点不足 :(1 )实验装置图有误。即从插头看 ,并没有接通电源 ,从灯泡看 ,灯泡已亮 ,说明已经接通电源 ,前后…     

巧用青霉素小瓶制作电解实验微型探究仪

针对传统电解实验方案的不足,介绍了用青霉素小瓶及必要的用品制作电解实验微型探究仪的研制过程和使用方法,指出了该仪器的优点和其他应用。     

微型电解实验探究案例

尽管实验探究被应用于中学化学教学中,但考虑到课堂时间和教学组织等一系列现实问题,一些老师还是会选择通过演示实验来完成相应的教学任务。比如在“电解”教学中,经常是教师先进行演示实验,然后师生共同总结电解的规律,课堂教学表面看起来“效率”很高,但学生从演示实验中获得的信息并不完整,一些实验现象根本就看不清楚,     

化学实验改进三则

1 氯化铜溶液电解实验改进 人民教育出版社中等师范学校教科书(试用本)第二册讲电解原理时,所做的实验是用2根石墨棒作电极电解U型管中的CuCl2溶液.     

铝作阳极电解氢氧化钠溶液的实验研究

铝是活泼金属,作为阳极电解氢氧化钠溶液理论上应该是铝失去电子成为铝离子溶解于氢氧化钠溶液。通过实验研究,可以得出铝作阳极电解氢氧化钠溶液实质是电解水。电解产生的氧气可以在铝电极表面形成一层不致密的氧化铝,所生成的氧化铝不溶于氢氧化钠溶液。     

用铜电极电解饱和食盐水实验的深度研究

用铜电极电解饱和食盐水,是苏教版《实验化学》教材中专题5的一个拓展实验,该实验选自于刘怀乐老师的《电解饱和食盐水的趣味实验》^[1],实验中用铜丝作阳极,产生了许多有趣的现象。但笔者用教材所给的装置进行实验时,发现不利于有些现象的观察。在对电解产生的沉淀物进行实验探究时,出现的现象与刘老师的叙述并不一样。     

Regeneration by Membrane Electrolysis of an Etching Solution Based on Copper Chloride

Regeneration of an acid solution for copper etching, based on copper(II) chloride, hydrochloric acid, and ammonium chloride, by membrane electrolysis was studied. The concentrations of copper(I, II) ions in the cathode and anode spaces, current efficiency, degree of copper recovery, and specific consumption of electric power at different quantities of electricity passed through the electrolyzer were measured. The influence exerted by the current density on the electric power expenditure for recovery of metallic copper was examined. The anode current efficiency by chlorine was determined with a spent etching solution and an H₂SO₄ solution used as anolyte.     

Nucleation of Gold Crystals during Electrolysis of Chloride Melts

Effect of electrodeposition conditions on the nucleation of gold crystals at a glassy-carbon cathode in an NaCl–KCl–CsCl melt at 500–700°C is studied by a galvanostatic technique. The maximum nucleation overvoltage can reach 550 mV. At low current densities, the surface of glassy carbon undergoes activation due to spontaneous deposition of gold crystals. The overvoltage vs. time curve for a melt containing an elevated (as compared with equilibrium) amount of chlorine exhibits additional wave that precedes the nucleation peak. The wave is probably connected with the recharge of ions of Au(III) to Au(I). The oxide film disappears from the cathode surface, thus facilitating the nucleation process. On a modeling electrode with a current leakage, an increase in the maximum overvoltage is discovered, which is not connected with the cathode activation. Exchange currents for the discharge-ionization of gold at the growing nuclei are estimated.     

Electrodeposition of a Palladium–Copper Alloy in Non-Steady-State Electrolysis

Effects of non-steady-state electrolysis modes on the electrodeposition of a Pd–Cu alloy are investigated. Using an alternating magnetic field, pulsed current, and cathode vibration widens the range of current densities where bright coatings may form and improves physicomechanical properties of the deposited alloy.     

对电解熔融氯化铝问题的思考

一般认为“氯化铝是分子晶体,熔融的氯化铝不导电,在电解槽中不能电解”,但这不是绝对的,我们可以改变它的环境,比如电解NaCl—AlCl3熔盐制铝[1],这一类似问题在中学教辅材料中早有体现,如电解Al2O3—Na3AlF6制铝,其中Na3AlF6的引入便是问题的关键,近年来Al在NaCl—AlCl3熔盐体系中的电沉积研究已经取得了很多研究成果[2],以下对电解熔融氯化铝问题进行分析。1电解熔融氯化铝问题的理论分析纯的氯化铝是无色的晶体,在通常情况下氯化铝容易挥发,180℃时开始升华,研究其蒸气密度表明在400℃以下氯化铝的分子式为Al2Cl6,氯化铝溶于有机…     

Structure of Partly Quenched Molten Copper Chloride

Abstract

The structural modifications induced in a model of molten CuCl by quenching the chlorine component into a microporous disordered matrix are evaluated using the hypernetted-chain closure in Ornstein-Zernike relations for the pair distribution functions in random systems. Aside from obvious changes in the behaviour of long-wavelength density fluctuations, the main effect of partial quenching is an enhanced delocalization of the Cu⁺ ions. The model suggests that the ionic mobility in a superionic glass is enhanced relative to the melt at the same temperature and density. Only very minor quantitative differences are found in the structural functions when the replica Onstein-Zernike relations derived by Given and Stell for a partly quenched system are simplified to those given earlier by Madden and Glandt.     

MgCl2-KCl-NaCl-CaCl2熔盐电解镁机理

在725℃温度下,对MgCl2-KCl-NaCl-CaCl2熔盐体系进行电解.研究结果表明,镁电解过程中阴极过电压ηc只有12～51 mV,电解过程的过电压主要是由阳极引起的;阴极还原过程的极限扩散电流密度id为1.56 A/cm2;镁离子阴极放电反应的电子转移数为1.98;2个电子转移步骤之前存在着前置转化步骤MgCl+ Mg2++C1-.应用循环伏安法对4种不同配比下的镁离子行为进行的研究结果表明,CaCl2质量分数从10%增加到40%,维持MgCl2质量分数为10%以及NaCl与KCl的质量比为6: 1不变,随着CaCl2质量分数的增加,镁离子结合成不易移动的络合阴离子,镁离子迁移的电流分数减小,镁离子的析出电位从-1.595 V逐渐负移至与钙、钠共同沉积,阴极峰值电流Ipc值逐渐增大,阳极峰值电位与阴极峰值电位之差的绝对值|φpa-φpc|逐渐增大,阴极放电反应的可逆性逐渐降低.     

Oxidation of Copper with Dicarbonylcyclopentadienyliron Chloride in Polar Solvents

Dicarbonylcyclopentadienyliron chloride oxidizes copper in dimethylformamide and dimethyl sulfoxide to give copper(II) chloride and dicarbonylcyclopentadienyliron dimer. The apparent kinetic characteristics of the process and the thermodynamic parameters of adsorption of reactants on the metal surface were determined. The reaction scheme was proposed.     

High-Performance Alkaline Seawater Electrolysis with Anomalous Chloride Promoted Oxygen Evolution Reaction

A highly selective and durable oxygen evolution reaction (OER) electrocatalyst is the bottleneck for direct seawater splitting because of side reactions primarily caused by chloride ions (Cl⁻). Most studies about OER catalysts in seawater focus on the repulsion of the Cl⁻ to reduce its negative effects. Herein, we demonstrate that the absorption of Cl⁻ on the specific site of a popular OER electrocatalyst, nickel-iron layered double hydroxide (NiFe LDH), does not have a significant negative impact; rather, it is beneficial for its activity and stability enhancement in natural seawater. A set of in situ characterization techniques reveals that the adsorption of Cl⁻ on the desired Fe site suppresses Fe leaching, and creates more OER-active Ni sites, improving the catalyst's long-term stability and activity simultaneously. Therefore, we achieve direct alkaline seawater electrolysis for the very first time on a commercial-scale alkaline electrolyser (AE, 120 cm² electrode area) using the NiFe LDH anode. The new alkaline seawater electrolyser exhibits a reduction in electricity consumption by 20.7 % compared to the alkaline purified water-based AE using commercial Ni catalyst, achieving excellent durability for 100 h at 200 mA cm⁻².     

Extractants for Copper Recovery from Chloride Solutions

Extraction of copper(II) from concentrated chloride solutions with hydrophobic pyridine derivatives containing electron-withdrawing substituents (ester and alkilamide groups) is discussed. Pyridine type extractants are effective reagents for recovery of copper(II) from chloride weakly acidic solutions. It is possible to select an appropriate structure of reagent to adjust its extraction ability to the composition of the aqueous phase.     

Molecular Orbital Calculations on Copper Chloride Complexes

The following paper describes a molecular orbital calculation of the Wolfsberg-Helmholz type. However, in contrast to the usual empirical determination of the H _ii integrals, these integrals are here computed from the wave functions of the free ions. The calculation is performed on Cu in a tetrahedral, square planar and octahedral environment of Cl, the results being subsequently compared.

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Zusammenfassung Die folgende Arbeit bringt eine M. O. Berechnung vom Typ Wolfsberg-Helmholz von Kupfer-Chlorid-Komplexen mit tetraedrischer, quadratisch-ebener und oktaedrischer Anordnung der Liganden. Die Ergebnisse werden miteinander verglichen. Abweichend vom üblichen Schema wurden die H _ii-Integrale mittels der Wellenfunktion des freien Ions berechnet.

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Résumé Un calcul O.M. du type Wolfsberg-Helmholz est effectué. Les intégrales H _iiy sont déter-minés des fonctions d'onde des ions libres, contrairement au procédé empirique usuel. Cu est traité en coordination tétraédrique, quadratique et octaédrique de Cl; les résultats sont comparés.