OTHER PROPERTIES OF ELECTROLYTIC SOLUTIONS 313 



When one or more electrolytes are dissolved in water, the resulting reac- 

 tion is influenced by the presence of these ions -due to the solvent. We 

 should expect similar reactions in the case of all solvents capable of 

 ionization. This includes, in the first place, solvents containing hydro- 

 gen, such as the liquid halogen acids, ammonia, hydrocyanic acid, formic 

 acid, acetic acid, the alcohols, the amines, etc. In all these cases, it is 

 to be anticipated that the solvent will furnish a positive hydrogen ion 

 and a negative ion corresponding to the constitution of the solvent. The 

 hydrogen or acid ion of substances dissolved in solvents which them- 

 selves yield a hydrogen ion will exhibit acid properties. The negative 

 ion, correspondingly, may be considered as a basic ion and salts of this 

 ion will act as bases when dissolved in a solvent yielding the same ion. 

 So, in the case of the alcohols, the acids exhibit acidic properties, while 

 the alcoholates exhibit basic properties. Similarly, in ammonia, the 

 ammonium salts exhibit acidic properties, while the basic amides exhibit 

 basic properties. On the other hand, a base typical of water, such as 

 tetramethylammonium hydroxide, would properly be classed as a salt 

 when dissolved in ammonia. However, many of the characteristic prop- 

 erties of acids and bases are not entirely dependent upon the presence 

 of a positive or a negative ion in common with the solvent. For example, 

 any salt of a strong base and a weak acid will exhibit properties. charac- 

 teristic of a base when in solution. Thus, tetramethylammonium hydrox- 

 ide in ammonia exhibits basic properties, very similar to those of potas- 

 sium amide, the reason for which lies in the fact that the resulting acid 

 formed by the hydrolysis, or ammonolysis, of this salt in ammonia is a 

 very weak acid water, which, as we know, is only very slightly ionized 

 in liquid ammonia. Correspondingly, a cyanide dissolved in water 

 exhibits basic properties for the reason that hydrocyanic acid is only 

 slightly ionized in water. Strictly speaking, an acid has a positive ion 

 and a base a negative ion in common with the solvent; nevertheless, 

 salts of strong acids and very weak bases and salts of strong bases and 

 very weak acids exhibit certain acidic and basic properties in solution. 

 We have seen that the OH~ ion is a characteristic basic ion only in 

 aqueous solution and that in other solvents other ions function as basic 

 ions. So, also, any positive ion common to a solvent will in that solvent 

 exhibit many of the properties of an acid ion. For example, iron intro- 

 duced into an aqueous solution of an acid yields a salt and hydrogen. 

 Similarly, iron introduced into molten lead salt yields a corresponding 

 salt of iron and metallic lead. Excepting for the fact that in the first 

 case hydrogen is a gas and in the second case lead is a liquid metal, 

 there is no essential distinction in the nature of the reaction in the two 



