# Calculate the Oxidation number of Sulphur in S2O82- ion.

The chemical formula of the given ion is S2O82-.

Let us assume the oxidation state of the sulphur (S) is X.

There are total eight oxygen(O) atoms, out of which two involve in peroxide linkage with oxygen state (-1) and remaining six oxygen(O) atoms, having oxygen state (-2).

Total charge on compound is

2 × X + 2× (-1) + 6× (-2) = -2

2X – 2 – 12 = -2

2X – 14 = -2

2X = 12

X = +6

∴ The oxygen state of the sulphur in the given ion is +6.