Ethylbis-2, 4-Dinitrophenylacetate, New pH Indicator Determination of Saponification Equivalents in Dark-Colored Oils

EA FEHNEL, ED AMSTUTZ

Index: Fehnel; Amstutz Industrial and Engineering Chemistry, Analytical Edition, 1944 , vol. 16, p. 53

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Citation Number: 5

Abstract

A new acid-base indicator, ethylbis-! 2, 4-dinitrophenylacetate, has been studied and its preparation described. The p H range over which the change from colorless to deep blue occurs is found to be from 7.5 to 9.1 (pK ca. 8.3), making the indicator suitable for most titrations which are ordinarily performed with phenolphthalein. The indicator gives an accurate end point in amber-colored solutions where the phenolphthalein end point is not ...