INCE 1923 when Fajans and Hassel (6) applied adsorption S indicators to the argentometric determination of inorganic halides, the use of these indicators for this purpose has become rather extensive (9, 10). I n the field of organic analysis, however, they have been used successfully only for semimicroanalyses. Bobranski and Sucharda (9,s) and later Hardy (7) using a 2-to 3-centigram sample for analysis burned it in an atmosphere of oxygen over a platinum catalyst. I n the case of chlorides and bromides the combustion gases were passed over barium carbonate and the resulting barium halide was titrated with silver nitrate using eosin or fluorescein as adsorption indicator. For iodides, a 40 per cent solution of sodium sulfite was used as the absorption liquid, and the iodide formed after removal of excess sulfite by barium carbonate was titrated with silver nitrate using eosin as an indicator. Holscher (8) burned the sample in an air stream and passed the combustion gases through a 5 per cent hydrogen peroxide solution. After buffering with sodium acetate, he titrated the halide formed using dichlorofluorescein or eosin as adsorption indicator.On a macroscale Bambach and Rider (1) found t h a t dichlorofluorescein could be used successfully in the case of inorganic halides and organic hydrochlorides in alcohol-water solutions. They suggested the possibility of applying this titration in conjunction with the Stepanow method of reduction to the determination of the halogen content of organic substances.In the work reported in this paper it was found that a combination of a modified Stepanow procedure and a subsequent titration with silver nitrate using adsorption indicators was a reliable and accurate method for determining the halogen content of a variety of organic halides. Experimental ProcedureThe procedure employed for the reduction of the organic halides was based upon the modification of the Stepanow method proposed by Cook and Cook (4). The amounts of sodium and alcohol employed were calculated from the empirical rules of Drogin and Rosanoff @), except for halogenated nitro compounds where the 150 per cent increase recommended b y Cook and Cook was used.A weighed sample of thoroughly desiccated organic halide (equivalent t o approximately 25 cc. of 0.1 N silver nitrate, except in cases of halogenated nitro compounds where an amount approximately equivalent to 10 cc. of silver nitrate was used in order to avoid too great dilution of the solution to be titrated) was placed in a 250-cc. Erlenmeyer fiask fitted with a reflux condenser, the constricted tip of which had been removed. In the case of solids the samples were weighed into small vials which were dropped into the Erlenmeyer flask. For the analysis of liquids, small vials were made by heating 6-mm. glass tubing until one end was sealed and pressing this end against a flat surface while soft. This tubin was then cut off at a length of 3 cm., resulting in a small vial wkch stood erect on the balance pan. During weighings the open end of the tube was close...

Quantitative Acetylation of Amines 2003 2. The benzoyl and o-chlorobenzoyl esters and 3. The structure of each of the seven phenols the -naphthylurethans of the seven phenols was established by synthesis.were prepared.East Lansing, Mich.

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The Potentiometric Determination of Arsenates 577 water and alcohol. The velocities increase in the orders given.2. The decompositions in water, and the decomposition of the sodium salt in alcohol, follow the first order law, but the decompositions of the anilinium salt in aniline and alcohol, and of the barium salt in alcohol, show an increase in the specific reaction rate as the decomposition proceeds. These departures have been explained on the basis of changes in the degree of ionization.3. The reaction velocity has been shown to be dependent upon the concentration of the trichloroacetate ion. It is suggested that the reaction is a unimolecular decomposition of the trichloroacetate ion.4. Temperature coefficients for the decomposition in the several solvents support the hypothesis that the stability of the ion is determined by the extent of solvation and the nature of the solvating substance.5. The formation of chloride ion in solutions of trichloroacetates in water and alcohol has been shown to be the result of an oxidation of the chloroform which results from the decomposition of the trichloroacetates.Madison, Wis.

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