- —*, oe 
Ss f 
Kreder— Quantitative Determination of Perchlorates. 291 
the bulb and serving for the passage of carbon dioxide. The 
side neck was sealed to one of two connected Will & Varren- 
trap absorption bulbs containing a solution of potassium iodide 
to receive the chlorine. After weighing the perchlorate into 
the flask and adding a sufficient amount of the powdered double 
chloride, all air was expelled by carbon dioxide and _ heat 
applied till the fused mass was raised considerably above the 
melting point and kept there for some time. Table V con- 
tains the results of a number of experiments performed in this 
way. 
TABLE Y. 
KC10,4 taken. KCl1O, found. Error. 
germs. erms. erms. 
(20) 0°0500 0°0438 0°0062— 
(21) 0°0500 0°0482 0°0018— 
(22) 0°0500 0°0460- 0:0040 — 
(23) 0°1193 0°1175 0:0018— 
(24) 0°1039 01018 0°0021 — 
(25) 0°0500 0:0477 0°0023— 
(26) 0°10038 0°0946 0°0057— 
These results came so close to being quantitative that a little 
help in the form of free acid seemed all that would be neces- 
sary to complete the reaction. But the addition of meta-phos- 
phorie acid to the cooled mass after the fusion in (22) gave no 
additional evolution of iodine. In (25) gaseous hydrochloric 
acid was passed in with the carbon dioxide in the hope of meet- 
ing the deficiency, but was evidently no improvement. One 
test in which meta-phosphoric acid was added to the fusion, 
resulted in such a violent evolution of hydrochloric acid that 
the whole contents of the flask was forced into the receivers. 
The results obtained by substituting (@) cadmium iodide and 
(>) anhydrous zine chloride for the double chloride of alumi- 
num and sodium are recorded in Table VI. In (27) (28) and (29) 
cadmium iodide was used and the iodine obtained by treating 
the cooled mass with dilute sulfuric acid (1:6) and potassium 
iodide for the reduction of cadmium oxide in each case added 
to that of the receivers. In (80) and (81), zine chloride was 
employed, but no additional iodine was obtained by treatment 
with sulfuric acid and potassium iodide. 
Taste VI. 
KC1O, taken. KC1O, found. Error. 
grms. grms. grms. 
(27) 01000 0°0745 0°:0255— 
(28) 0°1000 0:0693 0:0307— 
(29) 0°1000 0:0679 0°0321— 
(30) 0-1000 0:0245 0:0755 — 
(31) 0'1653 0°1156 0°0497— 
