硅酸及其盐的研究 ⅩⅪ.三甲基硅烷化-气相色谱法测定单硅酸的离解常数

由于硅酸的聚合性质,单硅酸易发生聚合,溶液中硅酸总量不能代表单硅酸的含量,因而其离解常数不易测准,各家所得数据不一.本文用三甲基硅烷化-气相色谱法测得硅酸溶液中单硅酸含量以求得不同时间下单硅酸的最快聚合点的pH,并以时间外推法求得单硅酸的标准离解常数.本文还用离子强度外推法,求得了单硅酸热力学离解常数。这些常数和公认值一致.

STUDIES ON SILICIC ACID AND ITS SALTS XXI. DETERMINATION OF DISSOCIATION CONSTANT OF MONOSILICIC ACID THROTRIMETH YLSILYL ATION-GAS CHROMATOGRAPHY

On account of the ease of polymerization of silicic acid, the polymerization reaction takes place when monosilicic acid dissociates, total amount of silicic aoid in its solution does not represent content of the monosilicic acid, so it is difficult to mrkc an accurate determination of dissociation constant of monosilicic acid. The values obtained by different invesugators usually do not agree. Thro trimcthyisilylation gas chromatography. the content of meaosiliore aoid in silicic acid solution has been determined in order that pH of the fastest polymerization of monosilicic acid through different time has been acquired . And according to time of extrapolation, standard dissociation constant of monosilicic acid has been determined Sy the way of ion strength extraplation in the present paper, thermodynamic dissociation consignt has also been determined. These constants are in good agreement with accepted values.