Tables of Aqueous Standard and Formal Potentials

S(s) 4- 2e- - S - A large number of measurements and calculated values are available. These vary from —0.48 to —0.58 V, but most are closer to -0.48 V 

Solid substances considered S (sulfur, light yellow, orthorhombic). 

H2S (hydrogen sulfide, colorless), HS (hydrogen sulfide ion, colorless), (sulfide ion, colorless), 82 (disulfide ion, orange), 83 (trisulfide ion, orange). 

In Fig. 2.2, the potential-pH diagram is represented for the stable equilibria of the system sulfur-water at 25 °C, i.e., equilibria comprising the forms H28, 

and S20g , which contain sulfur only in the oxidation 

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