18. Make electronic equation and specify which process - oxidation or reduction - occurs when the following conversions:
As3- → As5 +; N3 + → N3-; S2- → S0
On the basis of of electronic of equations arrange the the coefficients in the reaction equation,-reaching according to the scheme:
Na2SO3 + KMnO4 + H2O → Na2SO4 + MnO2 + KOH

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)