Volumetry of Hydrogen Micro-bubbles Dispersed in Water

Abstract

: When hydrogen gas is bubbled in water until saturation, micro-bubbles with ca. 0.5  m in diameter have been detected in water by the dynamic light scattering, reportedly. A part of saturated hydrogen may take gas form, whereas it may take hydrated form. A question is how much molar ratio of the two forms. If hydrogen molecule is oxidized to hydronium ion, the volume of the solution including bubbles should decrease by the amount of gas form more predominantly than that of the hydronium one. Herein we oxidized the saturated hydrogen gas with potassium permanganate in the presence of platinum wire as catalyst. The decrease in the volume of the gas was compensated for addition of water so that the pressure of the hydrogen gas was able to be kept to the atmospheric pressure. From the decrease in the volume under the steady state, concentrations of H 2 in the gaseous form were evaluated at several temperatures to be ca. 0.4 mM, which is a half the saturated concentration of H 2 . They were almost independent of the temperature of