Über die Oxydation verschiedener Pyrolyseprodukte an Jodpentoxid und Anhydrojodsäure

Summary

The reaction of different cracked products (H₂, C₂H₂, C₂H₄, COS and CS₂) with iodine pentoxide and anhydroiodic acid was investigated, because the cracked products develop iodine and thereby cause a positive error in the determination of oxygen. The development of iodine depends on the following factors: 1. on the chemical composition of the oxidation zone; much more iodine is developed on iodine pentoxide than on anhydroiodic acid; 2. on the cracked products, the development of iodine increases in the sequence H₂ < C₂H₄ < C₂H₂ < COS < CS₂; 3. on the temperature of the oxidation zone. The oxidation curves of COS and CS₂ are ascending steeply already between 40 and 50° C and coincide with the oxidation curve of carbon monoxide. The oxidation curves of C₂H₂, C₂H₄ and H₂ are shifted to higher temperatures.

The equations of the reaction between the cracked products and iodine pentoxide were found out. In the case of complete reaction the products give a multiple amount of iodine in comparison with carbon monoxide.

In the oxidation of C-containing cracked products also carbon dioxide is formed, besides iodine, but the amount of CO₂ is much less than the amount of iodine formed simultaneously. In consequence of this the determination of carbon monoxide in form of carbon dioxide is less disturbed by the cracked products than the determination in form of iodine developed.

Furthermore, the question was investigated, how far it was necessary to separate the cracked products. It was found, that under defined conditions it is not necessary to separate H₂. The unsaturated compounds disturb only when appearing in a larger amount. The S-containing cracked products however must be separated.