24 ROYAL SOCIETY OF CANADA 



value 1-75 as in decompositions at 500°. But the decompositions at 

 420°, 440°, and one at 460°, show on the other hand values of this 

 ïraction that are less than unity. Its values in these cases are: — 



This seems to indicate that at the beginning of the decomposition 

 reactions, a part of the chlorate molecules undergo an atomic re- 

 arrangement, into a form which is capable of uniting with an atom of 

 oxygen to form the stable compound potassium, perchlorate. If such 

 "he the case, and if the rearrangement takes place slowly the cause of 

 the low values of the above fraction is at once apparent. Otherwise 

 it is difficult to see why these values should not be as high at the 

 beginning of the reaction when the amount of unchanged chlorate 

 is at its maximum, as at a later stage when it has been more or less 

 diminished. That the constitution of potassium perchlorate differs 

 essentially from that of the chlorate, is, of course, evident from its 

 greater stability under the influence of heat, acids and reducing agents. 



The numbers given in Table 1 do not express the quantities of 

 the products in a manner which indicates the equation which is best 

 fitted to represent the reaction, but calculations from them are given 

 in Table 2, which are better adapted to this purpose. It was pointed 

 lOut in 1885 by Dr. Teed (Proc. Chem. Soc.) that not only in the com- 

 monly used equation: — 



2 KClOs = KCIO^ + KCl + 0. 



an erroneous one, but that no single equation will serve for all cases. 

 Individual decompositions can, he claimed, be expressed by equations, 

 of which the limiting ones are: 



10 KCIO. = 6 KCIO^ -f 4 KCl + 3 0^ 

 and 22 KCIO;, = 14 KCIO^ -f 8 KCl + 5 O2 



This was in a large measure confirmed by Frankland and Dingwall 

 in 1887 (J. Chem. Soc, 1887, p. 274). The equation which they 

 found best suited to reactions which were incomplete, viz.: 



8 KCIO^ = 5 KCIO^ — 3 KCl — 2 0, 



lies betwee-i the limits given by Dr. Teed. 



In Table 2, the total chlorate decomposed, is given the value 100, 

 and the weights of perchlorate, chloride, and oxygen, are therefore 



