[aeacfm]

what is the result of electrolysis of molten sulfates ? i mean at the anode

i think it would be S ulfur and oxygen or SO₂ also and oxygen
can some one correct

[DevaDevil]

in electrolysis, the anode will have the oxidation reaction.

Sulfate oxidation is not possible as far as I know, as with oxidation state of 6+, sulfur is in its most oxidized form.

[Enthalpy]

I'd have said O₂ and SO₂ SO₃, but ONLY IF these highly corrosive species don't corrode the anode, which must be extremely difficult with hot oxygen, more so as it tends to be partially atomic when evolving.

[aeacfm]

Sulfate oxidation is not possible as far as I know, as with oxidation state of 6+, sulfur is in its most oxidized form.

great sir , so do reduction of sulfate ( electrochemically not by bacteria ) possible . i hope

[Borek]

Sulfate oxidation is not possible as far as I know, as with oxidation state of 6+, sulfur is in its most oxidized form.

http://en.wikipedia.org/wiki/Potassium_persulfate

[aeacfm]

Great , does this step possible in aqueous solutions

Potassium persulfate can be prepared by electrolysis of a mixture between potassium sulfate and hydrogen sulfate at a high current density.

2 KHSO4 → K2S2O8 + H2
It can also be prepared by adding potassium bisulfate (KHSO4) to an electrolyzed solution of ammonium bisulfate (NH4HSO4).

Another reaction of its formation is the following (although the practical use of it is doubtable).

F2 + 2KHSO4 → K2S2O6(O2) + 2HF

or only in melts 

[aeacfm]

to ask the question in other words does  sulfate ion has tendency to react at cathod (in aqueous solution )