抄録
In order to determine the thermodynamic properties of sulphur dissolved in molten tin, the reduction equilibrium of sulphur in liquid tin by hydrogen gas was investigated for the temperature range 727-873°C.
It was found that the molten tin containig sulphur is regarded as an ideal solution within the limit of experiment. Experimental results are summarized as follows:
S (in liq. Sn) +H2=H2S; K=PH2S/PH2·[%S] =KP/[%S], log K=-2, 397/T+0.495, ΔF°C=10, 964-2.264T
Combining the equations with the published ones relating to the equilibrium constant of time formation reaction of hydrogen sulphide, time approximate equations expressed as a function of temperature for the dissociation pressure of sulphur dissolving in molten tin over the temperature range 727-873°C may be represented by the following equations:
2 S (in liq. Sn) =S2; K'=Ps2/[%S] 2, log K'=-14, 180/T+6.090, ΔF°=64, 860-27.86T
Furthermore combining the results observed with the equilibrium constants of dissociation of hydrogen sulphide calculated from the exact formula as a function of temperature, the values of log K' at experimental temperatures were calculated and compared with those from the above equation and then it was found that both values at each temperature agree with each other.
