전도도법에 의한 치환 피리딘들의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,金學成,尹永炷,朴義煥 慶北大學校 1984 論文集 Vol.38 No.-

Generally, pyridine and most of substituted pyridines act as base in aqueous solutions. The strengths of their basicities can be expressed quantitatively by the dissociation constant of base or its conjugated acid. Generally, the acidity of substituted pyridines can be expressed by K_a of the following reaction. ◁그림 삽입▷ (원문을 참조하세요) The dissociation constants of these subtituted pyridines have not been reported under high pressure but under atmospheric pressure. In this papers, the dissociation constants of some substituted pyridines were measured under high pressure by the conductometry. From the ionic conductivity of hydrogen ion, the dissociation constants (K_a) were calculated. The K_a values were increased with increasing temperature and were decreased with increasing presure. The charateristics of dissociation process of some substituted pyridines were deduced from the thermodynamic properties calculated from the dissociation constants.

Cupferron의 전극반응기구(제Ⅱ보)

黃金小,鄭倧在,黃正儀 釜山水産大學校 1976 釜山水産大學 硏究報告 Vol.16 No.1

In Previous paper polarographic and chronopotentiometric analysis of electrde reducction mechanism of cupferron in neutral and alkline media was mentioned. The electrode reaction mechanism was discussed in the aspects of current/electrode potontial and Vetter-Enyo's reaction order method in this experiment. from the results, it was reaffirmed that the electrode process of cupferron in alkaline aqueous solution is the ECE (charge transfer-chemical reaction-charge transfer) mechanism. The result of a technique of current/electrode potential showed the chemical reaction step of intermediate reactant was reversible and the rate determining step. Besides various parameters obtained in the experiment were also described.

海水로부터 우라늄의 濃縮分離

黃正儀,鄭倧在,李興洛 慶北大學校 文理科大學 1978 文理學叢 Vol.5 No.-

The present demand for all civil and military purpose exceeds a Korean surplus of uranium resources. Natural sea water is known to contain uranium in the mean concentration of about 3.3 ㎍ U/㎏ in the from of UO_2(CO_3)_3^4- solution. Though sea water has its trace quantity of uranium, its recovery by extraction method and untilization as energy sources at present is very remarkable in many nations. In this paper it was surveyed systematically the present world status in the extraction studies of uranium from sea water. Only a simple batch technique is described here, which permits an extraction of uranium from artificial and natural sea water. The basis of the technique is adsorption of the uranyl ion (UO_2(CO_3)_3^4- on solid adsorbent. The adsorbents were five kinds of activated TiO_2·H_2O series, titanium trihydroxy phosphate, zirconyl pyrophosphate, and zirconyl hydroxide. Of these adsorbents the most active material was TiO_2·H_O precipitated from the dissolved K_2TiF_6·H_2O in the 1 : 4 H_SO_4 aqueous solution by adding (NH_4)_2CO_3 solid until the pH of the filtered solution became 5.2. This extraction technique was successful to applying to the Korean beach sea water at Bizindo, Hansan-myun, Tongyung-gun, Kyungsangnam-do.

니켈-카드뮴 蓄電池중의 니켈極의 特性에 미치는 電解質의 影響

黃正儀,鄭倧在,金昌鎬 慶北大學校 自然科學大學 1986 自然科學論文集 Vol.4 No.-

Properties of the Ni(OH) electrode in Nickel-Cadmium battery are studied by the cyclo-voltammetric method in base solutions (LiOH, NaOH, KOH)at 20℃. The nickel electrode was prepared chemical precipitation of Ni(OH)_2 on the conducting substrate. The redox current ratio(ipa/ipc) which is closely related to the charge ratio of the Ni(OH)_2 electrode is greater than unity. We can conclude that OH^-ions have been inserted into the Ni(OH)_2 intersheets or adsorbed on the Ni(OH)_2 layers. The electrooxidation of inserted or adsorbed OH^- ions can be explained through a catalytic process involving the participation of Ni(Ⅱ)→Ni(Ⅲ) electrochemical reaction. The reaction products such as (OH) or OH^- also were retained in the defects of Ni(OH)_2 crystalline layers. The redox current ratio is increased by the existence of molecular oxygen in the electrolyte, because the number of OH^- ion in IHP may be increased by reduction of molecular oxygen. Voltammograms run in LiOH solutions are comparable to those recorded in NaOH or KOH solutions. In the same perturbation conditions, redox current ratio related to the Ni(Ⅱ)/Ni(Ⅲ) redox couple values in LiOH are greater than those obtained in NaOH or KOH. The effect of LiOH solution may be ascribed to the presence of highly solvated cations Li^+. In order that OH- ions can be closely adsorbed on the electrode surface, chemical work must be done to take off some water molecules from its primary hydrated sheath. It is guessed that solvated cations take up these chemical works. The sequence of redox current ratio is Li^+>Na^+>K^+.

고압하에서 혼합용매중의 몇가지 염의 전도도

황정의,오상오 慶北大學校 自然科學大學 1987 自然科學論文集 Vol.5 No.-

The equivalent conductance of magnesium chloride and magnesium sulfate soulutions have been measured at different pressures and temperatures varying the solvent composition of components. The conductances of most solutions were increased with increasing pressure but the values of MgCl_2 were decreased in the high alcohol content. The phenomenon indicate that the solvent separated ion effect is predominant in magnesium sulfate solution than in magnesium chloride or sodium chloride which shows the lower conductivities at the higher pressure. The activation energies for the eletrical conductance were remained in constant value of 2∼3 Kcal/mole. The ionization constants of salts were calculated from the conductivity data and physical properties by using the Shedlovsky's equation. The K_d values for magnesium sulfate varied in the range of 1.0×10^-3∼9.0×10^-3 at 20℃. These values are comparable with the values of 1∼10 for sodium chloride at 100℃. These abnormally large values are explained as the results of higher charge and lower temperature effect of magnesium salt than sodium salt. From the concept of the complete ionization constant the hydration number change is also calculated to be 8. 5. This value is slightly different from the sodium chloride.

기전력법에 의한 페놀 및 2-염화페놀의 해리반응에 미치는 압력의 영향

황정의,정종재,차성극 慶北大學校 1983 論文集 Vol.35 No.-

The dissociation constants of phenol and o-chlorophenol were measured by emf method and compared the effects of temperature and pressure with the ordinary state. The constants are varied with the temperature and pressure, i. e. those values are increased as the both temperature and pressure increased. As the hydrogen ion reverisible electrode, antimony-oxide electrode is qualified until pressure to 2,000 bar in ordinany temperature but at 35℃ only to 1,500 bar. From the observed constants, various thermodynamic properties are calculated and discussed on the dissociation reaction.

電氣的 開始法에 의한 2-Hydroxyethyl methacrylate의 重合과 이들 膜의 電氣的 性質

黃正儀,鄭倧在,車星極 慶北大學校 1978 論文集 Vol.25-26 No.-

The electroinitiated polymerization of 2-hydroxy ethyl methacrylate (HEMA) has been studied at the various voltages, from 2 to 2500 volts. The rate of polymerization was increased with increasing voltages. It was supposed that the orientation and migration effect of monomer accelerating the rate. The membranes were molded between two separated glass plates. These membranes have been used to measure the membrane potentials and the transport number of Na^+ ion and water. The measured membrane potentials and calculated values, which were related by Scatchard theory, gave satisfactory agreement below 0.1m. This was due to permselectivity of HEMA membranes, which had high fixed-OH group in the pore as a pendent. The main deviations of measured membrane potentials (E_c) and the maximum possible values of electrical potentials (E_max) were due to transport numbers of Cl^-ion and water. Therefore it seems to be make an useful strong hemodialysis HEMA membranes by electroinitiated grafting polymerization.

분광광도법에 의한 3-Chloro 및 3-Bromopyridine의 해리상수 측정과 그의 온도와 압력에 따른 영향

黃正儀,鄭倧在,尹永炷,金學成 慶北大學校 1984 論文集 Vol.38 No.-

Pyridine and most of substituted pyridines react as base in aqueous solutions. Strength of their basicities can be represented quantitatively by the dissociation constant of a base or its conjugated acid. The dissociation constants of weak acid or base are highly dependent on the pressure and the temperature. The dissociation constants of these substituted pyridines have been reported only under the pressure of atmosphere but not high pressure. In this study, we measured the dissociation constants of 3-chloro and 3-bromopyridine under high pressure by the method of spectrophotometry. Also, we obtained the thermodynamic parameters on the dissociation reactions that show the effects of the temperature and the pressure on the dissociation constants.

수용액중에서 아세틸피리딘류의 해리에 미치는 온도와 압력의 영향

黃正儀,鄭在元,鄭載植 慶北大學校 1990 論文集 Vol.49 No.-

The dissociation constants of 2-, 3- and 4-acetylpyridine were measured by conductometric method in the temperature range from 15 to 40℃ and pressure up to 2,500bar. The dissociation constants of these substituted pyridines were increased as the temperature increase but decrease as the pressure. From the data thermodynamic properties were calculated and the Hammett plat were obtained. From these properties the characteristic properties of the dissociation reaction were discussed.

기전력법에 의한 페놀 및 2-염화페놀의 해리반응에 미치는 압력의 영향

황정의,정종재,차성극 慶北大學校 物理化學硏究所 1984 硏究論文集 Vol.5 No.-

The dissociation constants of phenol and o-chlorophenol were measured by emf method and compared the effects of temperature and pressure with the ordinary state. The constants are varies with the temperature and pressure, i.e. those values are increased as the both temperature and pressure increased. As the hydrogen ion reversible electrode, antimony oxide electrode is qualified until pressure to 2,000 bar in ordinary temperature but at 35℃ only to 1,500 bar. From the observed constants, various thermodynamic properties are calculated and discussed on the dissociation reaction.