THERMODYNAMIC ANALYSES FOR S-H_2O SYSTEM AT 25℃

ＴＨＥＲＭＯＤＹＮＡＭＩＣＡＮＡＬＹＳＥＳＦＯＲＳＨ２ＯＳＹＳＴＥＭＡＴ２５℃①ＹｉＱｉｎｇｆｅｎｇ，ＣｈｅｎＱｉｙｕａｎ，ＺｈａｎｇＨｅｎｇｚｈｏｎｇ，ＺｈａｎｇＰｉｎｇｍｉｎＤｅｐｔ．ｏｆＣｈｅｍｉｓｔｒｙ，ＣｅｎｔｒａｌＳｏｕｔｈＵｎｉｖｅｒ...

A new type of potential pH diagram and distribution curves X(i) pH of aqueous species for the S H 2O system have been reported and discussed according to overall equilibrium principle. The stable region of elemental sulfur is dependent on total sulfur concentration C t(S) of all species in solution and partial pressure p H 2S / p 0 of H 2S gas. When p H 2S / p 0 =10 -6 and C t(S)=1 mol/L, the stable range of sulfur disappears. Dominant region of S 2- 5 ion in the solution corresponds to stable region of solid sulfur in E h pH diagram. This type of E h pH diagrams and distribution curves of aqueous species are of both theoretical and practical importance.