84 J. Bhaduri — Decomposition of [No. 2, 



the strength of the solution varies from 3 to 87 per cent, and the duration 

 of heating from one to six hours and a half. As the strength of the 

 solution diminishes the liberation of free oxygen increases. Comparing 

 the ratios of the decomposition products in Ai, ii, iii and Bi and ii 

 with D, 1 the nature of the decomposition is seen to vary perceptibly. 

 The solutions in D are gradually heated, and it is doubtful whether at 

 all they attain the temperature of 100° C. For the same weight of 

 chlorate formed the quantity of oxygen diminishes with the rapidity 

 with which the solutions are heated. In all probability, therefore, the 

 first application of heat on a rather strong solution of sodium hypo- 

 chlorite causes it to be entirely transformed into chlorate according to 

 the generally accepted equation 



3 NaCIO = NaC10 3 -f 9 NaCl. 



As the quantity of chlorate increases another reaction sets in : 

 2NaC10=2NaCl + 2 . 



These two equations being interdependent, I have not found it 

 possible to express the transformation by a simple equation. 



Note on the Decomposition of Mercurous Chloride and Estimation of Free 

 Chlorine. — By Jyotibhushan Bhaduri, M.A. Communicated by the 

 President. 



[Reed. 25th March, Read 1st April, 1896.] 



In the previous paper " On the transformation of hypochlorites " 

 mention was made of the fact that under certain circumstances a solu- 

 tion of sodium hypochlorite gave out chlorine. More recent quantita- 

 tive experiments 2 prove that in very nearly alkali-free solutions oxygen 

 and chlorine are simultaneously liberated. The analysis of such a 

 mixture without loss of unaltered hypochlorite is not an easy matter. 



The solution contains, to begin with, a chloride, hypochlorite and 

 a trace of chlorate. It may at the very beginning contain a small 

 quantity of free alkali, but after decomposition, especially when heated 

 from 150° to 160° C, the silica of the glass is dissolved by the alkali, 

 forming soluble silicates. Moreover, free alkali and free chlorine can 

 not exist side by side in the same solution. 



In neutral or alkaline solutions chlorides and chlorates of the alkali 



Separation of chlorine mefcals have n0 action on mercury. Free 

 and hypochlorous acid. chlorine combines with it, when the mercury 



is present in excess, forming mercurous chloride. Hypochlorites form 



1 Plate IV. 



3 The results of which will be communicated later on. 



