Acta Chimica Sinica ›› 1983, Vol. 41 ›› Issue (3): 279-283. Previous Articles     Next Articles

Original Articles

线性变位极谱研究 V:碲的吸附电流方程式

张祖训;吕欣平   

  1. 南京大学化学系
  • 发布日期:1983-03-15

Investigations on polarography with changing potential V: The equation of adsorptive current of tellurium

ZHANG ZUXUN;LU XINPING   

  • Published:1983-03-15

The mechanism of the electroreduction of Te(IV) has been studied, it is (TeO3)2- + 3H2O + 4e = (Teads)0 + 6OH- (1) (Teads)0 + H2O + 2e = (Hte)- + OH- (Teads)0 + 2e = Te2- The reaction scheme can generally be expressed as follows: ACcordingly, the equation of adsorptive current is give: i = 0.629 n2**2F**i/RT \n\(D0)1/2m2/3t7/6 \Pn\/(1+\Pn\)**2 (C0)* where \Pn\ = bAtA,7exp n2F/RT (E-E0)/& When \Pn\ = 1 the current reaches the maximum, ip = 0.157 n2**2F**2/RT \n\(D0)1/2m2/3t7/6(C0)* This equation shows that the peak current ip is proportional to m2/3t7/6, the ratio of potential change v and the concentration of the substance O being reduced. The half wave width, w1/2, can be obtained from the equation (6) in the form of the following expression W1/2 = 3.52RT/n2F The theoretical conclusions are in good agreement with experimental data for the adsorptive wave of tellurium in 0.25M NH3-NH4cl solution. The diffusion coefficient value determined agrees with that obtained by other polarographic method reported in the literature.

Key words: OSCILLOSCOPIC POLAROGRAPHY, TELLURIUM, ELECTROCHEMICAL REACTION, LINEAR TRANSFORM, ADSORPTION EQUATION

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