Absolute Sulfuric Acid, a Highly Accurate Primary Standard.

摘要

The accurate determination of the thermodynamic properties of aqueous sulfuric acid requires very exact analysis of the solutions. The preparation and use of the few existing reference standards capable of the desired accuracy (better than 0.01%) are involved and time-consuming. Absolute sulfuric acid, prepared by a maximum freezing point method, has been found suitable for use as a primary acidimetric and alkalimetric standard of extremely high accuracy. The accuracy of this and four other suiftiric acid rcference standards, as prepared and used during the present work, was found to vary from a few thousandths to a few hundredths of 1%. It is concluded that for a given amount of effort in preparation, the sulfuric acid standards are about tenfold more accurate than common previously existing standards. Constant boiling sulfuric acid, which can easily be prepared with an accuracy within 0.01%, is believed to be the most useful of the standards for general applications. (AN).