Determination of Water Content of White Fuming Nitric Acid Utilizing Karl Fischer Reagent

Abstract

in which the gas flow was slowed down to rates such as those encountered in practice, the recoveries are above 97.5%. This is considerably better than could be expected from the gravimetric method.Acetyl chloride is very easily hydrolyzed and in the presence of water only a small amount reacts with aniline to form acetanilide. This compound shows an absorption maximum at 240 µ in methanol (Figure 4). Chloroacetyl chloride quantitatively forms -chloroacetanilide in aqueous aniline. It also shows an absorption maximum at 240 m/j in methanol. APPLICATION TO STACK GAS ANALYSISThe precipitation of materials other than 1,3-diphenylurea may cause high results by the gravimetric procedure. This was emphasized by the analysis of two samples from a titanium chlorinator stack. The phosgene was precipitated as 1,3diphenylurea according to the procedure of Olsen and coworkers (7) and the precipitate was weighed. The precipitate was then dissolved in methanol and the 1,3-diphenylurea was determined by the ultraviolet method. The results are shown in Table II. As diphenylurea in the precipitate must inevitably be revealed by its absorbance, it is apparent that the gravimetric method was giving high results on these samples, particularly in the first case.