On the Oxidation of Ferrous Salts 247 



chlorate of potassium in dilute acid solutions does not neces- 

 >arily begin instantaneously. 



In Table III will be found the results of experiments on 

 tin oxidising effects of solutions of perchlorate, chlorate, and 

 nitrate of potassium acting on ferrous sulphate solution (c) for 

 different lengths of time at ordinary temperatures. The 

 mixture consisted in each case of 10 c.c. ferrous sulphate 

 solution (c), 20 c.c. H 2 SO 4 , 30 c.c. water, and 10 c.c. of one of 

 the oxidising solutions. 



TABLE III. 



From these results it will be seen that ferrous sulphate in 

 sulphuric acid solution, containing o-i gramme iron in 60 c.c., is 

 stable at ordinary temperatures in presence of the quantity of 

 nitrate or perchlorate of potassium necessary for the complete 

 "\ idation of the iron. In the case of chlorate the oxidation 

 goes on at such a rate that in one hour 30-2 per cent., and 

 in seven days 98-3 per cent, of the iron has been oxidised. 

 In connection with these experiments it was observed tli 

 clear solution of bleaching powder saturated in the cold. 

 oxidises ferrous sulphate at once and completely in the cold; 

 and that bromine water resemble < hloi potas-nun in 



requiring time, and being accelerated by a hi^h temperature. 

 The observations in Table IV were made with a view to 

 i a closer insight into the behaviour of chlorate <,t pnta^ium 

 -oiution at ordinary temperatures. 'I in- mixture exposed 

 m all cases 10 c.c. fermu- sulphate (< > hlorate solution. 



20 c.c. H 2 S(), iid 30 < In three blank experiments 



without ' hi 6 c.c. permanganate were used. 



