Acidified K2Cr2O7,CuSO4,H2O2,Cl2,O3,FeCl3,HNO3 oxidise aq. Iodide to iodine.
→ Alkaline KMnO4 oxidise aq. Iodide to IO−3
→ No reaction between aq. Iodide and Na2S2O3.
Reactions :
K2Cr2O7+7H2SO4+6KI→4KrSO4+Cr2(SO4)3+3I2+7H2O
2CuSO4+4KI→Cu2I2+I2+2K2SO4
H2O2+2KI→2KOH+I2
CP2+2KI→2KCl+I2
O3+2KI+H2O→2KOH+I2+O2
2FeCl3+2KI→2FeCl2+I2+2KCl
2KMnO4+KI+H2O→KIO3+2MnO2+2KOH
Na2S2O3 will not react with KI