IOWA ACADEMY OF SCIENCES. 
155 
Action of Chloric Acid on Zinc. 
Concerning the action of chloric acid on zinc there are 
many statements in the literature and some contradictions. 
According to GayLussac* and Berzelius the acid dissolves 
zinc without decomposition and with the evolution of 
hydrogen; according to Vauquelin, Fordos and Gelis f 
with the formation of hydrochloric acid, but without the 
evolution of hydrogen; according to Gmelin * with both 
the reduction of the acid and the evolution of hydrogen. 
Tommasi J states that in one experiment zinc reduced 14 
per cent of the free acid present in 100 hours, and that the 
acid was completely reduced by an excess of zinc and 
sulphuric acid. Zinc and zinc dust have been used as the 
reducing agents in determining chlorates, but not so far as 
known to me for the determination of the free acid, nor 
does there seem to be any record of quantitative study to 
determine the nature of the reaction of chloric acid and 
zinc so far as relates to the relative amount of zinc that 
reduces the acid and that which sets hydrogen free as the con- 
centration of the acid is varied. In the present series ex- 
periments were made with an excess of acid and with an 
excess of zinc, but the series is not yet complete. 
In these experiments and also in those with aluminium, 
there was used as the vessel in which the reaction took place 
a graduated tube made from a burette. It was fitted with a 
rubber stopper and a delivery tube of small bore, such as Is 
used for water thermometers. The tube was filled with 
acid nearly to the stopper when in place and adjusted in a 
water bath. The weighed zinc was dropped in, the stopper 
quickly inserted and the hydrogen was collected in a 
graduated tube over water. Experiments thus far seem to 
show that the relative amounts of zinc that set free hydro- 
gen and that reduced the acid may vary widely with the 
concentration of the acid. In the first two experiments 
weighed amounts of zinc were used and after the action 
had practically ceased the remaining zinc was weighed. 
In each case 25 c.c. of normal acid was used. The chloride 
*Gmelin’s Handbuch, Vol. 1, 370. 
t J. Pharm 4. 346. 
j Instituto Lombardi, 2 Ser. X, 799. Berichte 11, 345. 
