Polarograph 電流에 關한 硏究

金黃岩 成均館大學校 1962 論文集 Vol.7 No.-

Solution to the diffusion layer for the first reaction at a droping mercury electrode is presented. Equations are derived for polarographic currents for the reactions at the droping mercury electrod. A factor which is aplicabie to the droping mercury electrod is derived, when we use the equations of hte polarographic currents for the reactions at a plane electrode, and the rate constants of the backward reactions are negligible small, polarographic currents from a combination of diffusions and reactions are obtained at the droping mercury electrode with special approximation. Rate constant for reaction of ferrous ion with hydrogen peroxide is determined at the droping mercury electrode using the data of KOLTHOFF and PARRY for the kinetic current of ferric ion in the presence of hydrogen peroxide is good. Ratios of diffusion layer at the droping mercury electrode to the diffusion laver at the plane electrode are discussed and show that when the rate constants of the backward reactions for the first order reactions are larger then 1/0.05 sec^-1 and drop time about 3 sec., we cane use the equations of polarographic currents at the plane electrode to the droping mercury electrode. And, on the other hand, solution of the diffuison problem applicable to steady state reduction at the ideal streaming mercury electrode are presented, with special atention being given to the influence of stream contraction caused by the gravity. To eliminate the convection occuring in the layer between the streaming mercurry and electrolytic solusion. A new method have been invented, in this case the solution being tested was streamed with same velocity of the streaming mercury. Experiment have been made in order to compare the experimental value with the theoretical value and the experimental diffusion current was approached more to the theoretical value than the value obtained by earlier form of the streaming mercury electrode used by Heyrovsky.

EDTA 및 NTA 支指電解質중 Thallium (I) 의 Polarography 에 關한 硏究

김황암,김영태,Kim, Hwang-Am,Kim, Yong-Tai 대한화학회 1962 대한화학회지 Vol.6 No.1

The polarographic behaviors of Tl(I) was investigated in EDTA and NTA as supporting electrolytes for determination of Tl(I). A base solution containing 0.005 % gelatine, 0.1 M EDTA, and 0.05 M NTA was used. The halfwave potential of Tl(I) determined is -0.495 V v.s. S.C.E. in 0.1 M EDTA at pH 4.1 and -0.520V v.s. S.C.E. in 0.05 M NTA at pH 6.3. In this paper, the effects of gelatine concentration and pH values was investigated. The half-wave potentials of common elements was determined and compared with the half-wave potential of Tl(I).

水銀滴下電極에서 一次反應에 對한 포라로그라프電流에 關한 硏究

김황암,태창희,Kim, Hwang-Am,Chin, Chang-Hee 대한화학회 1962 대한화학회지 Vol.6 No.1

Solution to the diffusion layer for the first order reaction at a droping mercury electrode (D.M.E.) is presented. Equations are derived for polarographic currents for the reactions at the D.M.E. A factor which is applicable to the D.M.E. is derived, when we use the equations of the polarographic currents for the reactions at a plane electrode(P.E.), and the rate constants of the backward reactions are negligibly small. Polarographic currents from a combination of diffusions and reactions are obtained at the D.M.E. with special approximation. Rate constant for the reaction of ferrous ion with hydrogen-peroxide is determined at the D.M.E.,using the data of Kolthoff and Perry. The agreement of the equation with the data of Kolthoff and Perry for the kinetic current of ferric ion in the presence of hydrogen-peroxide is good. Ratios of diffusion layer at the D.M.E. to the diffusion layer at the P.E. are discussed and show that, when the rate constants of the backward reactions for the first order reactions are larger than 1/0.05 sec-1. and drop-time about 3 sec., these ratioes are about one.

Polarography 에 依한 Titanium 의 定量에 關한 硏究

김황암,김찬국,Kim, Hwang-Am,Kim, Chan-Kuk 대한화학회 1962 대한화학회지 Vol.6 No.1

Polarograph에 依한 分析方法을 利用하여 Ilmentite 鑛石에서 Titanium을 定量함에 있어서 鑛石을 酸처리하여 그 溶液을 器機에 提供함으로써 長時間 所要되는 在來의 分析方法을 避하여 迅速定量을 試圖하였다. 먼저 各種의 支待電解質에 對하여 檢詩하였으며 그 電解質에 對한 Titanium波의 定量感度와 共存하는 여러 Ion이 Titanium 波에 미치는 영향에 對하여 살폈다. 本實驗에서의 支待電解質로서는 근래에 Chelatometry$^{1)}$에서 많이 쓰이는 EDTA(Disodium etylenediamine tetraacetate)를 擇하였다. 支待電解質로서의 EDTA의 기초액 組成은 0,2M EDTA(pH=6)가 最適임을 알았다. 本支待電解質에서 Titanium의 Polarograph波가 大端히 良好하고 pH 6.3에서 $E_{1/2}$=-0.61V v.s. S.C.E.이면 또한 이 境遇에 濃度의 따라 波高가 比例하여 定量分析의 可能性을 보여 주었다. Titanium in solution of EDTA (Ethylenediaminetetraacetic acid) yield well-defined, reversible polarographic waves. In this report, a polarographic method for rapid determination of titanium in the Korean ilmenite was proposed, This polarographic method is based on the measurement of polarogram in the supporting electrolyte of EDTA. As the pH is increased the wave become more irreversible the diffusion current are diminished, and the half wave potential become more negative. In spite of the complication arising from numerous titanium species, in 0.2 M of EDTA, pH 6.3, the titanium waves are reproducible and analytically useful. In this medium titanium ion give well-defined reduction wave, and the half wave potential were -0.61V vs S.C.E. at pH 6.3. At the same time, the wave had a linear relationship between the concentration of titanium ion and the wave height. The Korean ilmenites were analyzed by this method and satisfactory results were obtained.

코발트(III)-Triethanolamine 錯鹽의 폴라로그라프波에 對하여

김황암,Hwang Am Kim 대한화학회 1963 대한화학회지 Vol.7 No.1

Cobalt(Ⅲ) ion gives two step waves with $E_{1/2}$-0.1V(?)(vs.S.C.E.) and $E_{1/2}$-1.37V(vs. S.C.E.) from a base electrolyte consisting of 0.1 M TEA+sodium borate+0.0002% gelatin. The first wave results from the reduction Co(Ⅲ) to Co(Ⅱ). The second wave corresponding to the reduction Co(Ⅱ) to Co(0) and this wave is diffusion controlled. The diffusion current constant of the second wave is 2.7. Under these-conditions, diffusion current of the second wave is proportional to the concentration of Co (Ⅱ) in the range of $10^{-3}{\sim}10^{-4}$ M.

Triethanolamine 질산鹽 基礎液中의 鉛(II)의 폴라로그라프波에 對하여

김황암,Kim, Hwang-Am 대한화학회 1962 대한화학회지 Vol.6 No.2

Lead ion gives a well-defined wave with $E_{1/2}$=-0.57V(vs. S.C.E.) from a base electrolyte consisting of 0.1M TEA=0.5M$KNO_3$=0.0002% methl red. (pH 9.8).The reduction wave of lead is lead(II) to lead(0) and electrode reaction of this wave diffusion controlled.Its diffusion current constant is 2.45 and temperature coefficient of this wave is about 1.2%.Under above conditions, diffusion current is proportional to the concentration of lead in the range of $10^{-3}$ ~$10^{-4}$ M.

Ni(Ⅱ)-Cyanide Complex의 還元에 關한 硏究

김황암,박일현,Kim, Hwang-Am,Park, Il-Hyun 대한화학회 1965 대한화학회지 Vol.9 No.2

水銀滴下電極에 있어서 Ni(II)-CN complex의 還元反應은 두가지 經路를 밟고 있는데, 一電子還元일때는 Ni(CN)42- + e [1]↔[2] Ni(CN)43- =(eq) Ni(CN)2- + 2CN- 그리고 二電子還元일 때는 Ni(CN)42- + 2e [3]--> 1/2[Ni(CN)33-]2 + CN- 이다. 反應 [1]이 反應[3]에 比하여 빠르게 일어나고 있다. $CN^-$濃度가 묽을 때 (0.004∼0.01M)의 還元波는 反應[1]에 依해 나타나며 이때 $CN^-$ 두個가 關與하게 된다. $CN^-$ 濃度가 增加하면 反應[2]는 빨라져서 反應[1]과 [2]는 平衡狀態에 到達하게 된다. $CN^-$濃度 0.2M 以上에서는 反應[3]에 依한 二電子還元으로 電極反應을 하게 되는데 이 反應機構는 $CN^-$濃度 0.004M일 때보다 8M때의 限界電流値가 約 2倍가 되는 現象도 說明할 수 있게 된다. Polarographic studies of reduction of Ni(Ⅱ)-CN complex on Hg-electrode have indicated that $Ni(CN)_4^{2-}$ is reduced by two paths, via one electron process Ni(CN)42- + e [1]↔[2] Ni(CN)43- =(eq) Ni(CN)2- + 2CN- and via two electron process Ni(CN)42- + 2e [3]→ 1/2[Ni(CN)33-]2 + CN- of which reduction [1] must be faster than reduction [3]. At very dilute cyanide concentration (0.004 to 0.01 M) cathodic wave is practically responsible for reaction [1] and two cyanide ions appear to contribute to the reaction. As increasing cyanide ion concentration the rate of oxidation reaction [2] catalysed by Hg increases and reaction [1] and [2] approach to equilibrium. Therefore, reaction [3] represents the cathodic wave at high concentration of cyanide (above 0.2 M). This mechanism can also explain the fact that limiting current at $[CN^-]$ = 8 M is approximately twice of that at 0.004 M CN.

Polarograph 에 依한 Monazite 鑛石속의 Uranium 의 定量에 關한 硏究

김황암,손병영,Kim, Hwang-Am,Son, Byong-Yong 대한화학회 1961 대한화학회지 Vol.5 No.1

A polarographic method for rapid determination of Uranium in the presence of foreign ions was proposed. The method is based on the measurement of polarogram in the sulfuric acid as supporting electrolyte. In this medium Uranyl ions give well defined reduction waves, and half-wave potentials are -0.19V vs. S.C.E. as first wave, and uncertain volt. vs. S.C.E. as second wave in $2.4 N-H_2SO_4.$ The first wave has a linear relationship between the concentration of Uranyl ion and wave height. The author also studied a method for rapid determination of Uranium in Korean monazite sand without eliminating the foreign ions. The Korean monazite sands were analyzed by this method and satisfactory result were obtained.

EDTA 適定에 依한 닉켈 定量

김황암,김영태,Kim, Hwang-Am,Kim, Yong-Tai 대한화학회 1961 대한화학회지 Vol.5 No.1

The nickel has been separated and precipitated with dimethylglyoxime in the usual manner and dissolved the precipitates with hydrochloric acid. To the nickel solution, 0.2g of Murexide as an indicator and 5 ml of 20 percent tri-ethanol amine solution were added and titrated with a standard solution of EDTA. At the end point the color changes from yellow to deep purple. In this paper, the purpose is that conditions for titration and for separation from the interfering substances were investigated and a suitable procedure was found and applied on the determination of nickel in Korean nickel ores.

Polarography에 依한 Ti(IV)의 黃酸 complex에 關한 電極反應機構

金黃岩 成均館大學校 1968 論文集 Vol.13 No.-

Polarography에 依한 Titanium ion의 硏究는 많은 inorganic radicle과 organic complexing agent로 行하여 졌다. 이들 硏究는 制限된 範圍에서의 取扱이여서 分析的 目的에는 滿足할만한 結果를 얻었으나 Ti-complex의 糾明과 電極反應 機構에 關해서는 그다지 進展을 가져오지 못했다. Titanium의 free ion이 hydrolysis를 하는 것, 큰 overvoltage를 가지는 것은, 이 Ti-complex를 糾明하는데 어려움이 되며, polarographic wave가 anomalous kinetic current를 수반하므로 문제가 까다로워 진다. 適下水銀電極에서 oxalate와 tartarate의 Ti-complex가 reversible 한 還元波를 나타내는데, 이는 Pecsok 等에 依하여 硏究되었으며, 各種 酸인 HCl, H_2SO_4, HNO_3, H_3PO_4 支持電解質에서도 reversible 한 波를 나타내어, 여러 硏究家들에 依하여 考察되었고, 分析에 應用되고 있다. Ti(Ⅳ)은 酸溶液 中에서 TiO^(2+)로 存在하며 電極反應에 依한 還元은 free ion에서 보다 더 복잡한 機構로 進行되리라 본다. TiO^2+ 自體의 還元 TiO^2++2H^++e→Ti^3++H_2O ……(1) 은 큰 overvoltage를 가질 것으로 豫想되며, 이는 noncomplexing agent인 HCIO_4에서 아주 irreversible한 還元을 함이 實際 證明해 준다. 이 비가역성은 Ti과 O와의 bond때무에 큰 energy를 소비해야 하는 것으로 보여지며, Titanyl ion이 complex를 만들면 쉽게 還元이 이루어질 것이다. 黃酸 支持電解質에서 Ti(Ⅳ)의 還元을 Gierst와 Lienard^(1)가 共同 硏究하였는데, 이들은 波가 둘로 分離됨을 알았다. 이에 對한 解析으로 첫波는 kinetic wave이며, 波高는 黃酸 濃度에 比例하고, 黃酸 濃度 0.2M/L 以下에서는 消失되며, 3M/L 以上에서 둘째波인 diffusion의 wave는 없어지고, 첫波가 diffusion current의 性格을 갖는다고 했다. 이는 黃酸 濃度가 클 TiO^(2+)이 水素 ion이나 黃酸 ion과 反應하여, 쉽게 還元되는 complex ion를 만들기 kinetic wave Ti(OH)SO_4^++H^+↔Ti(OH_2)SO_4^(2+) Ti(OH_2)SO_4^(2+)+H^++e→Ti(OH_2)HSO_4^(2+) A new method, which was the quantitative treatments of the kinetic currents at a specially restricted condition, was introduced to study the electrode reaction of the system Ti(Ⅳ)∼Ti(Ⅲ)―H_2SO_4 and could develop the mechanism. In the solution of (NH_4)HSO_4 1 M/L or H_2SO_4 0.5 M/L, the cathodic waves of Ti(Ⅳ) spilt into two waves (kinetic and diffusion). The mechanism of the kinetic wave is: Ti(OH)SO_4^++H^+↔Ti(OH_2)SO_4^(2+) Ti(OH_2)SO_4^(2+)+H^++e→Ti(OH_2)HSO_4^(2+) The mechanism of the diffusion wave is: TiO^(2+)+HSO_4↔Ti(OH)SO_4^+ Ti(OH)SO_4^++H^++e→Ti(OH_2)^(3+)+SO_4^(2-)