In acidic medium dichromate ion oxidises stannous ion as: xSn2++yCr2O2−7+zH+⟶aSn4++bCr3++cH2O
Dichromate ion in acidic medium oxidizes stannous ion as
x––Sn2++y–Cr2O2−7+z–H+→a––Sn4++b–Cr3++c–H2O then
xSn2++yCr2O2−7+zH+→aSn4++bCr3++cH2O