ANALYTICAL CHEMISTRY
888 will stimulate the interest of other workers in the field. Although the investigation was conducted primarily with paints, the analytical procedures should prove useful in the Mtitration with potassium iodate in a strong hydrochloric acid solution x i t h formation of iodine monochloride, to several hj-drazincl salts. The potentiometric study of this reaction in at least 4 b' hydrochloric acid was found b y Singh (IO) to give accurate anti reproducible results with a sh:irp inflect,ion point whew using :I platinum foil electrode versus a calomel cell. Stelliny (11) reported that the potentiometric titration of hydrazine n i t h iodic acid gave iodine as an end product in sulfuric acid solutions :tnd iodine monochloride in hydrochloric acid solutions. Bray and Cuy (3) found that the oxidation of hydrazinc t o nitrogen in 0.5 to 2.0 N eulfuric acid was complete in 3 minut(+ when treated with a known excess volume of iodic acid. The excess iodic acid was determined by reduction t o iodine n-itli potassium iodide and titration with potassium thiosulfate. T h r oxidation of hydrazine by iodine (5)was found t,o be rapid i n alkaline solution and slow in acid solution. I n the presence of sir in alkaline solution hydrazine undergoes slow decomposition due to a reaction with oxygen. By proper addition of reagent:: this decomposition was minimized t o give agreement within 0.2YG of theory.
tions on the iodate reduction is studied i u both the presence and absence of chloroform. Recommended potentiometric procedures for the quantitative determination of hydrazine sulfate are described. Because potentiometric procedures may be varied to a greater degree than most generally accepted methods allow, it is probable that the hydrazine nitrogen in other compounds may be determined by a proper choice of one o f the procedures described.
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