Elements of physical chemistry

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...action of hydrogen ions. Catalysis.--The inversion of sugar, as well as all other reactions of the first order which are hastened by the action of acids, is apparently due to the ionized hydrogen which is present. This action is known as a catalytic action of the acid present, which retains throughout the reaction its original concentration. The reason why H' ions should act in this way is unknown; but that they do have an accelerating effect is an established fact. In general a catalytic action is one that hastens the reaction in which it is without at the same time having its concentration changed by the reaction. An example of such an action is given by the increased speed of solution of metallic mercury, silver, or copper in a nitric-acid solution in which one of these has already been dissolved to a slight extent. The catalytic action here is due to the formation of the oxides of nitrogen, these, when passed into the nitric acid from an exterior source, causing the same action as the above. Since the catalysor takes no part in the reaction it does not alter the equilibrium constant, hence it must also has u k ten the reverse action, so that Tj may remain constant. As there is no general law known for catalytic action the reader must be referred elsewhere for the vast number of isolated facts. The more concentrated the acid used the more rapidly the sugar is inverted, without, however, any exact proportionality. The inverting action increases more rapidly than the concentration. In presence of a neutral salt of the acid its inverting power is increased by about 10% for the stronger acids, but decreased for the weaker ones. Since the acceleration of the speed of the reaction is caused only by acids, and since they are distinguished by the presence of H' ...