189 



Nascent State of the Elements. 



By J. H. Ransom and R. A. Stevens. 



It is well known that some of the elements at the instant of libera- 

 tion from their compounds or when in contact with certain other materials 

 are more chemically active than under other conditions. This so-called 

 "nascent state" has for more tlian sixty years been assumed to be due 

 to tlie atomic as distinguished from the molecular condition of the ele- 

 ments. 1 n some of the more recent texts this explanation has been re- 

 placed either by one liased u])on thermodynamics or by that known as 

 "contact or catalytic action." 



The principle of thermodynamics is that those reactions will be most 

 apt to occur which are accompanied with the greatest degredation of 

 energy. On this principle is explained the fact that hypochlorous acid is a 

 better oxidizing agent than free oxygen. The former decomposes with the 

 evolution of heat and therefore the total energy evolved during oxidation 

 with it is that much greater than would be produced with the use 

 of free oxygen. Or as Mellor (Inorganic Chem., p. 400) says regarding 

 nascent hydrogen, "Its greater activity is ascribed to the energy of tlie 

 reaction being available for inaugurating another reaction rather than 

 being frittered away as lieat." This is a fundamental principle and no doubt 

 influences if it does not determine the course of reactions. But it does 

 not seem to explain why iodic acid, which decomposes with the absorption 

 of almost as much heat (per atom of oxygen) as hypochlorous aC'id evolves, 

 oxidizes liydrogen iodide, in solution, much more rapidly than does free 

 oxygen. 



The contact e.xplanation assumes that tlie presence of certain sub- 

 stances in contact with reacting materials increases the velocity of the 

 action between those materials solely by its presence. According to this 

 theory tlie increased activity of nascent hydrogen is due to its contact 

 with the metal at the instant of liberation. If the presence of the contact 

 agent forms the only difference between the active and inactive hydrogen 

 then it would seem that Intimate contact of the latter with the more posi- 

 tive metals should cause It to become active. This explanation of activity 

 appears less fundamental than that due to the atomic condition of the 



