KMnO4\mathrm{KMnO}_{4}KMnO4
NaOH\mathrm{NaOH}NaOH
K2Cr2O7\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}K2Cr2O7
Na2 S2O3\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}Na2 S2O3