A METHOD FOR THE DETERMINATION OF 
CHLORIC ACID. 
BY W. S. HENDRIXSON. 
In the methods for the determination of chloric acid by 
reduction, metallic zinc in some form and ferrous sulphate 
have been the reducing agents most used, though sulphur 
dioxide and formaldehyde have also been employed. The 
conditions under which the two former reducing agents 
have been used have been much varied. Thus Thorpe and 
Eccles * used the zinc-copper couple, and determined with 
a solution of silver the chloride formed from the chlorate. 
Bothamley and Thompson f showed that the results by 
this method were too low unless sulphuric acid was added 
near the end of the reduction to dissolve any basic salts of 
zinc. By the same method Becker J found the results too 
low and preferred to use zinc dust and a little copper sul- 
phate. Fleissner § used zinc dust and boiled the neutral 
solution one hour, but Becker attained complete reduction 
only by using a large excess of zinc dust with sufficient 
sulphuric acid to dissolve it completely without the aid of 
heat. 
Stelling || reduced chlorates by long boiling in an alka- 
line solution of ferrous sulphate, and determined the 
resulting chloride. Becker found that the reaction was 
very slow and incomplete, and recommended a neutral 
♦Jour. Chem. Soc. Lond., 11, 541; 14, 856. 
fJour. Chem. Soc. Lond., 58, 164. 
j Repert. d. Anal. Chem., 1, 877. 
§Zeit. d. Anal. Chem., 20, 115. 
||Zeit. d. At al. Chem., 6, 32. 
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