Influence of Oxygen, Sulphur Dioxide and Moisture on the Homogeneous Combination of Hydrogen with Sulphur

Abstract

PREVIOUSLY¹, we have shown that minute traces of oxygen lead to an apparent increase in the rate of formation of hydrogen sulphide from its elements, as judged by the iodine titre of the resulting gaseous products. The increase was ascribed to a catalysis by oxygen, though we pointed out that “the effect of so minute a quantity of oxygen is remarkable and unexpected”. The subject has been systematically investigated using hydrogen containing known concentrations of oxygen ranging from 0.06 to 7 per cent by volume, at temperatures between 290° and 343° C. The method adopted, a static one², was carried out in Pyrex bulbs containing quantities of sulphur which, whilst always sufficient to combine with the oxygen present several times over, were yet insufficient to leave any liquid at the temperature of the reaction. The products consisted of a mixture of sulphur dioxide and hydrogen sulphide together with the excess of sulphur and hydrogen. The amount of each compound was ascertained by an iodometric titration followed by a gravimetric estimation.