4 Kneciit & VtkTYJS, Boiling Points of Aqueous Solutions. 



reduced to a certain point (for KCl about 2\ volts) the 

 amount of electrolysis will be theoretically nil* 



The following experiments were done with a view to 

 ascertaining how much electrolysis actually does take place. 



A lO per cent, solution of KCl was put in the apparatus 

 and a current of 7 amperes passed for 4 hour. 



The liquid was then titrated for chlorate by means of 

 titanous chloride, and it was found that only 02 per cent, 

 of the KCl had been converted into KCIO;,. 



A 10 per cent, solution of KI was treated with 7 

 amperes for I hour. The liquid was then titrated for 

 iodine by means of thiosulphate (after acidifying). 



Found — Iodine (free and as iodate) 05 per cent, on the 

 weight of KI. 



A 10 percent, solution of KI treated with "jl amperes 

 for f hour. 



Found — ro per cent, iodine (free and as iodate). 



A 2 per cent, solution of crystal scarlet was treated 

 for 30 minutes with 6\ amperes, and was then titrated 

 with titanous chloride. 



Foujid — I'S per cent, of the dye destroyed. 



In the above experiments the currents used are 

 slightly greater, and the time much longer than would be 

 the case in carrying out a determination. 



It is evident, therefore, that by using a heating coil of 

 low resistance the amount of electrolysis which takes 

 place is negligible. 



Measurements of the molecular elevations produced, 

 have been made with several clcctrolj'tes and non-electro- 



* This was shown to be the case in another apparatus in whicli the 

 resistance of the heating coil at ioo° was 0'32 ohms. With a current of 

 7 A amps, this would correspond to 2*2 volts. With a io% solution of KCl, 

 and boiling for half-an-hour under these conditions, no chlorate was 

 produced. In this apparatus the electrolysis of KI was less than in the 

 other one. 



