Sciencemadness Discussion Board

Found sodium peroxydisulfate from denture cleaner extraction?

symboom - 29-11-2018 at 09:38

Has anyone used this as a source the package says sodium persulfate unfortunately I don't have anymore potassium iodide to see if it will precipitate iodide or sodium bromide for bromine to test it's strength

[Edited on 29-11-2018 by symboom]

AJKOER - 29-11-2018 at 15:07

I would add it to aqueous (NH4)2SO4 and freeze out the Na2SO4, leading aqueous ammonium persulfate.

If you can isolate the dry salt, it can create, intentionally or not, dangerous (explosive) energetic mixes (like with any metal or alloy with a high anodic index) as:

S2O8(2-) + 2 e- <---> 2 SO4(2-)

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In addition to a very powerful oxidizing agent, one can use it for a source of sulfate radical anions with an activator metal (like tiny dose of cobalt ions in one of its lower oxidation state).

Co(ll) --> Co(lll) + e-

e- + S2O8(2-) = SO4(2-) + •SO4- (see p. 11 and p. 12 at https://etd.ohiolink.edu/rws_etd/document/get/ucin1130533674... )

Example of reaction with NaCl:

Cl- + •SO4- = •Cl + SO4(2-)

•Cl + •Cl = Cl2

•Cl + Cl- = •Cl2-

Speed of the reaction is fastest with I-, then Br-,.....
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Light (definitely UV not sure about solar light) may also form a radical:

(S2O8)2- + hv ---> •SO4- + •SO4- (p. 11 same source)

Note, p. 12 Eq (3.14) shows a slow decomposition reaction of persulfate in water to H2O2.

[Edited on 29-11-2018 by AJKOER]