Excerpt from Oxidation and Reduction in Organic Chemistry From the Standpoint of Potential Differences: The System Hydroquinone and Quinone According to the van't Hoff equation or the principles of chemical equilibrium, a reducing or oxidizing agent, in solution absolutely free from any of its product, should have a potential of infinity (minus or plus). Therefore, since so-called pure solutions of oxidizing or reducing agents do not show infinite potentials, the presumption is that they contain quantities of products sufficient to account for the potentials observed, though too small to be detected by analytical means. Actual calcula tions from existing experimental data will show that the concentrations of these substances can be that small without the theoretical potentials being any larger than those actually found for pure solutions, which are usually of the order of about I volt, and never more than two. This is reasonable enough, for, if the solution were so pure as to give a potential greater than this, its oxidizing or reducing power would be so great that, we would expect it to react with the water, or anything else available producing product until the excessive tension was relieved. Measure ments on so-called pure agents are therefore to be taken, as quantitative data, with more or less reserve, as we. Are not justified in assuming that these indeterminately small quantities of products present may not vary greatly, relatively speaking, in different specimens, even though a par ticular series of measurements has given fairly reproducible results. One more point may be mentioned. Mere potential measurements, Without a correlation of some sort, prove nothing even qualitatively. Any two solutions containing electrolytes 'will give a potential difference, due to the relative discharging tendencies of their ions, even when no oxidizing or reducing agent is added, unless, by a rare coincidence they happen to have practically the same oxidizing potential. 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.