Showing papers in "Transactions of The Faraday Society in 1919"

Pyridine and ammonia, estimation and separation—an application of the electrolytic dissociation theory

Abstract: This theory as a quantitative working hypothesis has inade it possible to predict the course of titrations from the electrochemical constants involved, i.e. the ionisation constants of the acids and bases which are being titrated. The results obtained with this guidance in the case of pyridine ammonia mixtures have been used to establish analytical methods, and the information gained as to the conditions o€ distillation may also be of value to the ammonia industry. The acidimetric titration of the mixed bases, either before or after distillation, has evidently not found much favour with analysts, and the methods adopted for pyridine itself depend upon entirely different reactions, such as the formation of crystalline CdCI,?C5H,N in presence of alcohol (official German method), or in the case of traces of pyridine, the precipitation as periodide, C H N*I,, in strong sulphuric acid solution.” In the latter process the pyridine is, however, finally determined by titration with alkali, using methyl-orange, which is apparently the standard. indicator for this purpose, but according to the author’s experience had better be replaced by another indicator. 5. s