Hydrogen Ion Concentration In Solution Research Articles

Contrasting effects of chlorides and sulphates on the hydrogen ion concentration of acid solutions

In the course of an investigation upon the effect of neutral salts upon hydrogen ion concentration we have noted a striking contrast in the effect of chlorides, sulphates and magnesium salts on the apparent hydrogen ion concentration of solutions of hydrochloric and of sulphuric acids.The results of our measurements are given below. In all cases a solution of acid was mixed with a solution of a given salt and diluted to 100 c.c. The concentration of this solution of the mixture was always 0.1 normal with respect to the acid and that particular concentration of the salt whose effect upon the hydrogen ion concentration was to be studied. The hydrogen ion concentrations were measured two days after the solutions were made up.The effect of chlorides in increasing the hydrogen ion concentration of hydrochloric acid solutions is not new. This has previously been shown by Harned1 and by Fales and Nelson2. Arrhenius3 found that the hydrogen ion activities of acetic and of hydrochloric acids were increased by neut...

The Use of the Colorimeter in the Indicator Method of H Ion Determination with Biological Fluids

In recent years it has become essential that physiologists, bacteriologists, and biochemists generally shall be able to determine accurately and conveniently the approximate actual reaction or hydrogen ion concentration of solutions or media of various types. It is almost inconceivable that any extensive work with biological solutions, including fermentation products and culture fluids, may proceed without adequate consideration of this factor. It is clearly recognized that as an absolute standard in the measurement of the H ion concentration of solutions one must rely upon the use of the hydrogen electrode, whether with or without the more recent developments in the way of direct-reading potentiometers. Nevertheless, the electrical or gas-chain method requires considerable physico-chemical experience and a type of apparatus not commonly available to the physiologist or bacteriologist. To students working in the fields just mentioned and employing nutrient solutions, decoctions, plant juices, the products of fermentation, etc., the indicator method in its present standard of development makes a strong appeal. This is true because: (1) an adequate degree of accuracy is usually attainable by this means, especially if the standard solutions are occasionally checked by the electrometric method; (2) the indicator method has special application where the quantity of material available may be small and the determinations need to be made promptly, as occasions