1896.] 



Hypochlorites to Chlorates. 



69 



trated sulphuric acid and 2 c.c. hydrochloric acid, required 28'2 c.c. per- 

 manganate, or 00392 gm = l c.c. permanganate. 



Cii) 1'4874 gms. of the double salt in presence of dilute sulphuric 

 acid only required 379 c.c. permanganate, or 003924 gm. = 1 c.c. per- 

 manganate. 



These two numbers are very nearly the same, and in fact agree 

 more than might be expected. Other estimations gave precisely similar 

 results. 



Having thus convinced myself of the applicability of the perman- 

 ganate method in hydrochloric acid solution, a solution of pure potas- 

 sium chlorate containing 001 gm. of available oxygen per gram of the 

 solution was made, and the following test experiments performed. 



Two grams of the dried chlorate when ignited left a residue of V2176 

 grams of KC1. Therefore oxygen present is 39" 12 °/ while the calcula- 

 ted quantity is 39'16 %. Also 1 c.c. Sn Cl 2 is equal to 6 - 35 c.c. perman- 

 ganate, and 1 grm. permanganate is equal to 0'00554 gm. Iron. 



(i) 1568 gms. Sn Cl 2 + 5055 gms. KC10 3 required 358 c.c. per- 

 manganate. 



.-. Available oxygen= (15-68 x 635 - 35"8) X '^^ 



= 0-05047 gm. 

 (ii) 16-149 gms. SnCl 2 +5-014gms. KC10 3 = 39-1 c.c. permanganate. 



.-. Available oxygen = 0'05026 gm. 

 (iii) 3 - 41 gms. double salt + 5047 gms. KC10 3 = 242 c.c. perman- 

 ganate = 24-2 x 0054 = 0-1341 gm. Iron. 



.-. 5047 gms. KC10 3 = 0-05043 gms. oxygen, 

 (iv) 312 gms. double salt+5 - 039 gms. KC10 3 = 17 c.c. perman- 

 ganate. 



.-. 5039 gms. KC10 3 = 0-05036 oxygen. 



Method of experiment. 



Sn Cl 2 method. 



Ferrous Ammonio- 

 Sulphate method. 



No. of experiment 



I 



II 



Ill 



IV 



Estimated value 

 C alculate d value 



0-05047 

 0-05055 



005026 

 005014 



005043 

 0-05047 



005036 

 0-05039 



(iii) The solution of the chlorate was distilled with pure concen- 

 trated hydrochloric acid in Bunsen's distilling bulb. Various other 

 acids (boric acid, phosphoric acid, acetic acid, sulphuric acid) were tried. 

 The first three failed to decompose the chlorate. As calcite was used 

 to carry off the chlorine, &c, from the bulb to the absorption apparatus. 



