Excerpt from Technical Methods of Chemical Analysis, Vol. 1: Part II OF the methods used for the determination of potassium, that of Fresenius, in which the potassium is separated as potassium platini chloride, is the most important, and has found general acceptance in the potassium salt industry. Amongst other methods, the determina tion of potassium as perchlorate, which has been very thoroughly worked out: by Wense 1 and by Caspari,2 may be regarded as of equal value with the older platinum method, a statement substantiated by the fact that the International Congress for Applied Chemistry (1903) decided to class it as an international method of determination, together with the Fresenius method. A. The Potassium platinichloride method - In the separation of potassium as potassium platinichloride by Fresenius' shortened method, which has been thoroughly worked out by Precht,3 the use of pure platinic chloride solution is of the utmost importance. It must be free from platinous chloride and oxides of nitrogen, and contain at most only a small quantity of free hydrochloric acid. Precautions must also be taken to guard against the introduction of other impurities, such as sulphuric acid from impure reagents, and potassium platinichloride from the incomplete washing of recovered platinum from platinum residues. The preparation of the platinic chloride solution is described below. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.