混合溶媒中の酸-塩基指示薬の動向(I)

加藤 晧一

doi:10.2116/bunsekikagaku.13.514

混合溶媒中の酸-塩基指示薬の動向(I)

DOI Web Site Web Site

加藤晧一

東京大学物性研究所

書誌事項

タイトル別名

The behaviour of acid-base indicators in the mixed solvents (I)
コンゴウヨウバイチュウノサン-エンキシジヤクノドウコウ 1

この論文をさがす

抄録

The behaviour of acid-base indicators in the mixed solvents as water-alcohols, water-acetone are investigated, mainly on their absorption spectra in each medium from which are calculated pH and pK_i of those indicators. <BR>With increasing organic solvent concentration, pK_i, of sulfophthalein indicators as B. T. B., B. C. G. became larger while those of azo indicators as D. Y., M. R. became smaller. <BR>According to this results, phosphoric acidpotassium hydroxide titration curves in several conditions are described in details. <BR>In pure water, the first equivalent point of phosphoric acid is pH=4.3, but in methanol mixture (about 66.6%), the point became 6.1. On the other hand, the color change point of B. C. G. is 4.64 in water but was 5.7 in 66.6% methanol solution.